How can you read an excessive number of pages in a short amount of time? I'm taking 3 online classes. Each has a book I have to read. Each chapter is around 100 pages long in all of them, and I have a week to read them. I'm not able to do some of my assignments, because I'm having to spend so much time reading. I'm having to read so much I'm not even absorbing all the material, and I'm starting to get a head ache from doing nothing but reading nonstop all day.

I'm losing my mind and I don't know what to do. I just don't see how I can absorb that much information so quickly. If you want to know what my classes are, they're World Religion and two programming classes. Yeah. Over the course of five days, I have to read 60 pages per day! And yes, I have to do it in five days, because otherwise I won't have enough time to do any of my assignments.
One trick is to find out what the prof wants you to get out of the book, and just scan the pages for anything relevant.  You can skip over paragraphs that introduce ideas you already know or present ideas that aren't relevant to the course.  

Another trick is to use Amazon books to do this for you... do a search through the book for course key words and just read the sections around those words.

If you just need to learn the subject, and it's impossible to apply tricks for this, prioritize your time: study the table of contents, line by line.  Read the introduction and one chapter from somewhere in the middle.  Read the conclusion.

At the same time, read the Wikipedia articles for the subject of each book... or for the book itself, if it's well-known enough.

When you go to answer homework using any of these tricks, you will "know the book" well-enough to go back and find the answer you need somewhere in the pages.

Unfortunately I can't say whether these methods will get you anywhere: perhaps these courses really do just require more time.