I have decided to take up mountain biking as I've discovered sick trials behind my house in san diego. I have a 200 dollar mountain bike (bought for school initially) and am looking into becoming serious in this sport.
can someone please recommend some beginner books/magazines for me to read/learn??
As mentioned above, get Ned Overend's book Mountain Bike Like a Champion. You can probably find it on Amazon. Excellent way to learn technique as it's very easy to read/understand and he's won 5 nationals and the first world title. It covers some racing, but the emphasis is on techniques which are the same for just riding for fun.
If you like the book, he's also got a very nice video Performance Mountain Biking, the Basics and Beyond.
'08 Bianchi C2C Alum/Carbon Ultegra/105 Mix, '06 Santa Cruz Chameleon
Besides the books, find a club or stop into the local LBS and hang out, talk, learn. Join the group rides, if they have them. This will really help you practice the techniques you read about in the books and mag. The only way to learn is to ride, IMO.