http://en.wikipedia.org/wiki/Chaos_magic
The concept behind chaos magic is that the most powerful thing in magic, and the only thing necessary to work magic, is belief. If you believe that drinking a glass of milk at 3pm for three days will give you good luck, it will. If you believe that you can use an untuned TV or radio for divination, you can.
The chaos magician has the entirety of magical practices, beliefs, deities, etc open to him. He can use any of them that he chooses, for a lifetime, or for a single hour, depending on his needs and his preference.
Chaos magic also places emphasis in creating your own path. Rather than following a generic spell or ritual word for word, you can reinvent it, or come up with your own. It's considered a very good thing to be able to design your own spells or rituals based on the things that you personally find meaningful. For me, that means mixing dream magic, comic book characters, servitors, herbalism and the Hellenic pantheon, because those are the things that capture my interest and the things that give me results.
I use chaos magic for everything.
Chaos magic, with belief, is actually extremely easy. Because it's so free-form, I would imagine that it's easier than most outlined magical paths. I started using chaos magic in elementary school, before I knew it had a name, by drawing sigils on my body in ink that matched my skin color.
It does not require devotion, and I would postulate that, by definition, such devotion would be discouraged, or seriously lessen the power of the magician. People who like ritual and have the creativity for it, but find the LBRP tedious, should probably try chaos magic. XD
I'm not sure if servitors are unique to chaos magic, though I imagine not. Servitors are entities created by the magician to serve a certain purpose. They are (AFAIK) not physical, but they may be very powerful, and they can be created for a wide ranges of reasons. Some are created by magicians in order to protect themselves or others. Some are "guard dogs". Mine hang around, alerting me to things I may not otherwise notice.
http://www.chaosmatrix.org/library/chao ... rvitor.txt
That link has a very interesting approach to the creation of servitors.
Actually,
www.chaosmatrix.org is a really fantastic site full of information about the history and evolution of chaos magic, as well as a good number of delicious insights, practices and rituals.
If you have other specific questions, I'll be happy to answer.
As for books, Liber null, Liber KKK and SSOTBME are my recommendations.