Many people are interested in reading and studying the Bible but find it difficult to understand and become discouraged. The following are some tips that may help you understand it better and enjoy it more:
1. Like any other book, the Bible builds on itself. There is plenty you can understand without having read the whole thing, but to properly understand its overall message, imagery, deeper themes, and repeated references you really need to take the time to build a working knowledge of the whole book. The more you know about it, the more readily you'll be able to link passages together and form complete pictures of what is being presented (and the quicker you'll recognize error when you hear it). Cults and false teachers would not be nearly as successful as they are if people had a broader base of Bible knowledge from which to draw.
2. Context, context, context! Some of the worst mistakes people make in their efforts to understand the Bible (and what it reveals about God himself) are rooted in taking scriptures out of their context. This is especially problematic in Paul's epistles, as Paul regularly engages in lengthy discourses about the topics he covers. Base your reading around themes rather than individual verses or the scriptures parceled out in suggested reading guides. For instance, if you want to understand Hebrews chapter 6, you're going to need to understand chapters 1 through 5 first. This is going to require some time and effort, but there is simply no other way to properly understand scripture.
Understand that the Bible is not laid out like an encyclopedia; very seldom will you find everything you need to know about a subject (like salvation, for instance) in one passage, unless it's a historical reference (speaking of a particular event). Make a habit of searching for all occurrences of terms related to subjects you're studying (Bible computer programs like E-Sword and websites like Bible Gateway and Blue Letter Bible make this easy). Also, learn how to use cross-references, which are passages of scripture that may be related in some way to the passage you're reading at the moment. Cross-references are often found in the margin of many Bibles, especially study Bibles, and can be very helpful.
3. Do your best to avoid reading the Bible through "lenses" provided by books, study guides, and popular teachers. As good-intentioned as most of these are, virtually everyone brings preconceived notions and doctrinal biases to their teaching, and it's easy to fall into the habit of trying to understand the Bible according to what Dr. So-and-so thinks. One of the best things I ever did was to read the Bible from cover to cover without any particular doctrines and perspectives in mind, just allowing it to speak for itself. Be sure you believe what you believe because you, personally, are convinced of it rather than because someone you respect is convinced of it. Remember that the vast majority of pastors and teachers come from denominational institutions that were established to defend and perpetuate certain theological belief systems.
If you consult study guides, start off with theologically-neutral resources such as Bible dictionaries, interlinears, and concordances rather than with commentaries. These things will help you understand the text without necessarily coloring your view of it. I would avoid commentaries until you have broad base of biblical knowledge from which to draw.
4. Bear in mind that the Bible was not written in English; it was originally written in Hebrew, Aramaic, and Greek, and has been translated into English. If in doubt as to the meaning of a particular word or passage, do a word-study. A word-study is an examination of the original language from which our English Bible was translated, and can be done quite easily using a program like E-Sword (which is free) or a site like Blue Letter Bible. Translators mean well but they're not infallible. They occasionally make mistakes and sometimes translate passages with certain theological biases in mind. Also, part of a translator's job is to make a text comfortable to read, so there are times when they will translate a passage of scripture in a manner that obscures the precise meaning; this happens a lot with verb tenses, and can impact your ability to understand a passage correctly.
Attempt to learn how the original audience to whom a book or passage was written would have understood it (a Bible handbook or dictionary can help with this). Don't assume that an ancient reader from the Middle East would have understood a concept the same way an American would today.
5. Find a reputable, understandable translation. If you picked up the King James family Bible your parents were given when they got married, and find it difficult to understand clearly, there's a reason for that: you're reading English that is 400 years out of date. A lot has changed in our language in all of that time, and you may find that the Bible opens up to you in a whole new way when you try reading it in modern English. Among the translations I recommend are the New King James Version, the New American Standard Version, and the English Standard Version (I've used all of them a great deal). For study I also recommend Young's Literal Translation; it's a bit wooden and awkward for general reading purposes, but it's excellent for gaining a better knowledge of the original text of the scriptures without having to consult Hebrew and Greek study tools (although I certainly recommend consulting these resources once you're comfortable enough to do so). I also recommend the Septuagint (the Greek translation of the Old Testament) once you've built up a good, general foundation of scriptural knowledge.
One further note on this: some people are partial to the King James Version, for a number of reasons, and I respect their preference. Others, however, will argue that it's the *only* preserved Word of God in English, and vehemently argue against the use of any other translation. I'm very familiar with this debate, have studied the issue out for myself, and completely disagree. Yes, there are Bible versions you should avoid (in particular The Message and the New World Translation, the latter of which is a cult translation), and there are versions that I would not recommend until you have established familiarity with more strictly accurate versions (such as the New King James and New American Standard) - the New International Version (NIV) is a prominent example in this middle category; but don't let this become a stumbling block for you. There are plenty of resources online and in print that address this issue. If you feel the need to get into the matter, consult what *both* sides have to say and then make an informed decision. Don't let people intimidate you. Many who sound off on this come across as authoritative but really have little idea what they're talking about.
You may also find it very helpful to compare translations, as they tend to bring out different nuances that can be helpful in understanding the scriptures. I've seen this proven many times. And for those who do enjoy older English, I recommend trying the Geneva Bible.
6. Be willing to make the time investment. Just like any other discipline, understanding the Bible takes time; but if the Bible really is what it claims to be (the Word of God), what else could be more worthwhile than coming to know it better?
7. Ask the Lord to open your understanding as you read (Luke 24:45). As the one who inspired the scriptures, only he can really bring out the full force of its truth. Often, you'll find that he will do this based on what you need at the moment. I've experienced this a number of times, and as much as I've read and studied the Bible over the years, I'm still finding new things in passages I've read dozens of times.
8. Study with others. If you're a Christian, you're a member of the Body of Christ, and each member of that body has been granted unique gifts that are designed to help strengthen the entire body. While the Lord will certainly speak to you in your own private devotions, it is wise to call upon the experience and understanding of other believers as well, and especially those who have been believers longer than you. They may see things that you've overlooked and may think of things that would never have occurred to you otherwise.
9. Take notes and/or post thoughts on what you've read. Often, when you read and study the Bible you'll come across items of interest that you may want to recall later and/or return to for further study. For that reason, it's a good idea to write down references to the passages you read and any immediate thoughts you have on them. You may even want to consider blogging or otherwise posting your thoughts on social media. This can serve two purposes: a) It serves as a way of remembering what you've read and learned, and b) your thoughts might be of benefit to others.
10. Above all - apply what you learn! The Bible contains much that is transformative, but in order for this to occur, it must be applied to our lives. Start doing something with what you learn as you read the Bible, and you'll find that God will give you even more understanding. Like any good manager, God is not in the habit of giving his valuables to those who won't do anything productive with them.
May God bless you richly as you come to know him better through his word!