+1 for Eli's X3 videos from Groove 3. I have both.
His Melodyne Video is great, too.
The X2 Power book would do you well with X3, but I would be tempted to hold on to your friends X1 book for as long as possible, and buy Scott's X3 Power book when it comes out.
Speaking as some one who actually has X1, X2 and X3, the X1 book will get you a lot of the way there,. Watch Cake's Seth Perlstein's "Transitioning from X1 to X2" video, Eli's X3 video (and maybe the X3 New Features) and you'll be fine.
That should keep you going until Scott's X3 Power comes out. Which you should then buy.