Browse bookstores like Borders.
Read book review magazines like New York Times book review, Publisher's Weekly.
Browse your local library's bookshelves.(new releases and fiction, mystery, etc section that appeals to you.)
Ask friends/family what they are reading and see if they liked the book.
Browse a list like the 101 Great books recommended for college bound students.(This list has some old, classic best
sellers. www.greatschools.net)
I am one person who has not read the Harry Potter series or
Lord of the Rings and don't plan on reading that series,
On Thursday in USA Today they have the top 50 books and have reviews of new releases.
I hope that this will give you some places to look or get ideas for new books.(One more thought have you joined a book club that might be available at your local bookstore or library.)