....I would like to know if it is possible to learn kitesurfing without taking any lessons, but with the help of educational materials such as books and dvd/video......
Since you're apparently not substantially mentally or physically deficient, the short answer is yes it is possible.
How safe (or dangerous to you and others) and easy (or frustrating and time consuming) it will be compared to taking a certain number of lessons is impossible to judge without knowing a vast amount of detail regarding your particular situation. These two factors translate into risk and unpleasantness.
So it effectively boils down to , how much risk and unpleasantness will you eliminate per dollar spent on lessons and is it worth it. Perhaps lessons are especially expensive where you are. On the other hand, they might be comparatively cheap.
Nobody but you can judge how valuable your dollars are to you. For example, since I have less disposable income than many people, I tend to value my lonely dollars higher than someone with lots of disposable income. You sound like you have a similar attitude in this regard.
On the other hand though, I dislike risk more than many people and put a relatively high value on my recreational (kiting) time.
With the philosophy out of the way, there are some practical things that you should be able to learn to help you analyze the amount of risk and reduce the potential for unpleasantness.
Can you arrange to learn in an especially safe location?
Can you make sure to learn what specific dangers may be associated with your location(s) and how to mitigate them?
Can you obtain a helmet, impact vest, reliable wind meter, and a reasonably easy to use kite in the proper size to be able to practice in the lowest amount of wind practical?
Can you make sure that all your equipment, and especially your quick releases, have no defects and work properly?
Can you practice activating them until it is automatic (read the thread " Safety Release Reflex (SRR) ")
Can you arrange to have a backup quick release for your quick releases?
Can you arrange to learn in the bottom half of the wind range for your kite (at least until you have a good clue)?
Can you obtain reasonably reliable help and advice for free from local kiters (if you're a hot chick, you'll be able to get lots of other bonuses as well)?
Can you have a helper on hand with medical training? (just kidding, medical training is nice but hopefully unnecessary).
Obviously, a knowledgeable instructor would make obtain the foregoing info etc. a lot easier and faster and the info should be more reliable.
Although wherever you buy your kite might throw in showing you how to land and launch your kite (try to get them to do it, they should know everything about it), being able to land and launch your kite reasonably safely BY YOURSELF is probably the most critical skill you'll need and it might behoove you to get detailed instruction at least for this. At the same time, you might be able to get any specific questions answered which your studying of the above didn't resolve.
(310) - 430 - KITE (5483)
The BEST way to learn kitesurfing since 2002 !