Books that are formatted for people with dyslexia are difficult to find. When I was creating the Dyslexic-Friendly Book List for beginning readers (http://dyslexickids.net/_Book_List_.html), I went page-by-page through thousands of books only to find 100 books that were suitable for children with dyslexia. The rest were too difficult to read. Most publishers seem to be completely unaware that their books are not accessible to a large percentage of the population. However, there are some exceptions.
Barrington-Stoke books in the U.K. (http://www.barringtonstoke.co.uk/) and Stoke Books in the U.S. (http://www.stokebooks.com/) publish books that are designed for students who have difficulty reading.
Stone Arch Books uses a special font that is easier to read, as well.
Several of the classics have been published in the Open Dyslexic font and are available on Amazon: http://www.amazon.co.uk/s/ref=ntt_athr_dp_sr_2?_encoding=UTF8&field-author=Mr.+Laurence+Francis+Harrison&search-alias=books-uk&sort=relevancerank
Audio books are always a good option, as well. Here are 10 sites to download free audio books: http://dyslexic-kids.tumblr.com/post/34754008086/10-sites-to-download-free-audio-books-if-youre
Textbooks in audio format can be found from a few sources, from Learning Ally to Amazon. http://www.nysl.nysed.gov/tbbl/textbook.htm