there are many websites such as the ASL browser, etc. that help with learning sign. There are some good dictonaries, many of which I have. There are also some really good books, such as A Loss For Words, that can help you learn a lot about deaf culture. BUT...
Books and online tools are best used for REVIEW, it is REALLY hard to learn signs from a book or even from a video, especially when you've never taken a class. Many people sign incorrectly and don't even realize it, this especially includes signing to themselves, esp. with fingerspelling, when they have no one to practice with. Even reviewing with books doesn't always work, because signs vary from place to place a LOT, and new signs are developing all the time. By the time a sign gets published in a dict., it may be out-of-date.
As from what I can tell, you haven't taken a sign class yet, I would trust John, who's been in an ITP, and his advice. Good luck with your signing, and I hope one way or another, you become fluent and a positive part of the deaf community!