Lightroom 3 questions

I recently upgraded to a 1D. Time for better editing/organizing software. I've tried the free trial of LR in the past, but got discouraged because I was unable to access any built-in instruction. Also, I apparently made the mistake of importing all of my photos, only a couple thousand, and ended up with two and three and sometimes four copies of each. My collection was growing like a Petri dish.

But, I want to try it again. Where is the best place to buy it? I see student prices at $60, which I don't qualify for, all the way to list of $300.

What's the best way to learn how to use it? I see online tutorials by Adobe, Scott Kelby, Julieanne Kost, Michael Tapes and others. I missed a shot at a two-day in-person course for $300 here in Minneapolis.

I'm interested in putting in some effort, but I don't want to be heading down the wrong path and just wasting money and having to start over at square one.

Any advice will be appreciated.