It can be hard to get used to a completely different script. My advice is:
1. read the box on the right "Novels for the kanji-phobe".
2. try reading something you are familiar with already in English (or your native language). For example: detective stories have a fairly predictable pattern - crime is committed, police arrive, they take statements/fingerprints, talk to people and then arrest someone. You just need to pick up some specific vocabulary (fingerprints, police ranks, evidence, forensics...) and you will be able to understand it.
3. read the book in English first and then in Japanese - at least then you'll know what to expect! Or read a review of the book in English on Wikipedia.
4. Just do it. Practice makes perfect, so making a commitment to read a sustained piece of text every day (even a newspaper article online, for example) will help.
What to read when your Japanese isn't very good yet?
1. children's stories
A bit basic but it's a good start, even if everything is in hiragana and it's hard to tell where the words begin and end.
Have a look at this series of folktales:
Manga Nippon Mukashi Banashi
There are as many as 60 of these, and they are based on a cartoon version on television. In fact, many are up on YouTube - read the book (Taue jizo, UniM ERC EA 5938 N654 v.8) and then watch the 10 minute YouTube clip! (The clip has been removed, but keep looking - sometimes they come back.)
2. junior high school level books
These are generally real books, but with furigana (the reading) of each kanji next to it. Try this series of famous stories:
Nijūisseikiban shōnen shōjo Nihon bungakukan (UniM ERC EA 5933 N004 - there are 20 volumes altogether)
Even if you can't read all the text, just having a go and understanding the story by looking at the pictures will help. See what's on the shelves at 6359.5 xxxx.
The Nihongo Noryoku Shiken （Japanese Language Proficiency Test/日本語能力試験・にほんごのうりょくしけん）is held each July and December and is a useful way of gauging how good your Japanese is. The test is administered from Japan, and you are one of hundreds of thousands of students taking the test all around the world.
The test has changed format from 2010. Previously the levels were 1 (near-native, used for entry to a Japanese University) to 4 (basic). Now they are N1 (most difficult) to N5 - see here for more details.
The JLPT website offers sample questions, details of where the tests are held, and suggestions of books to practice from. The Japanese Collection has some of these books, which include CDs for listening comprehension exercises. Search the catalogue for "noryoku shiken" as a keyword and find the books which have N1, N2, N3, N4 and N5 in the title. The books using the words 1-kyu, 2-kyu, etc are the older ones, and still might be good practice.