google "reddit Chaos Magick" and pick the ones that you like for further research.  this is a vast subject and no one can claim his knowledge is superior to the others so you had to do your own digging really.

Phil Hine is a good resource--his Condensed Chaos is a frequently recommended primer for beginners and you can find an updated online version of it here titled Oven-Ready Chaos: http://www.occult-underground.com/hine.html Peter Carroll's Liber Null and Psychonaut is another classic.

Have fun!

From Theoccult private tracker, the most downloaded book (2670 times) in Chaos Magic category is:

  Ramsey Dukes - Sex Secrets of the Black Magicians Exposed - An Essay On Sex Magic (1974)

The runner-up, which has almost 1,000 fewer downloads (1807 times), is this book:

  Jan Fries - Visual Magick

The book "Peter Carroll - Liber Null & Psychonaut" recommended in the last post, ranked #10 in number of downloads (1049 times)

Theoccult private tracker has the most occult and magic books in one place, as far as I know, and there are very knowledgeable members in the subject of occult and magic, so these rankings may provide some valid reference value.  Just an FYI, I have zero knowledge of the subject matter.

Seconding "Visual Magick" and "Condensed Chaos."

Also highly recommending Patrick Dunn's "Postmodern Magic" and Aidan Wachter's "Six Ways."

Condensed Chaos is a very small book that has 68 pages of text and practically no graphics/pictures/illustrations, it is a very basic introduction of Chaos Magick and a very easy read.

Visual Magick is also an absolute beginner's intro book, but it has 191 pages thus covers a much greater ground with more details, and the book is full of visual illustrations.

I think these 2 books are a good place to start for anyone who is curious about the subject.  I have always been a visual learner since before I can read any text, so the 2nd book works a lot better for me personally.