Improving your English through extensive reading means reading everything and anything: choose interesting and easy books (only a few unfamiliar words per page; most of these words can be guessed from context or are not very important). Graded readers from major British publishers are an excellent choice. You can read these books in a library (many also have CDs or MP3 files), or buy them yourself.
One special thing about Cambridge English Readers is that many of their titles are stories about modern people. Some of these stories are quite interesting to read. The Big Picture, for example, is a book about an unlucky Japanese photographer: his camera almost kills him!
Macmillan Readers has quite a few well-written books. Even I, a native speaker of English, enjoy reading them for their simple style.
http://www.macmillanreaders.com/reader_level/starter
There are 649 titles in the Oxford Bookworms Library, many of which are classics (famous old books which are STILL interesting, even today)
Many Penguin Readers are based on famous movies. Watch the movie, then read the book, or read first, then watch. You will enjoy yourself better that way. Level Two includes several titles: here you read and listen to a small sample from Mr Bean (printed and audio).
http://www.penguinreaders.com/members/pr/students/sample-area.html
http://www.penguinreaders.com/members/pr/students/sample-area.html
