For reading comprehension, there is also a list of books to read to sharpen your RC skills. It's divided into recent classic fiction, heavyweights, and non-fiction. If you read through the replies, there are even more suggestions.
I don't have 5 posts, so it won't let me post the link, but search the forum for: "Books to Read (Improve Verbal Score and Enjoy a Good Read)"
What might be even more helpful is to join a book club, perhaps. Discussing what you read is often one of the best ways to improve comprehension, IMO.
Of course, this isn't to say that you shouldn't be doing more formal methods of practice as well. Extracurricular reading is just a beneficial addition to the standard test prep.