A bit vague there aren't you? you want to do motion stuff and video in your 'Motion Graphics' s/w. Well, that's what it's for isn't it? IS there szomethign specific you really want to do or are you just having trouble getting started woth After Effects?
What version do you have?
If you just want tutorials then google terms like "Adobe After Effects tutorial" and you'll find more than you'll ever have time to read/watch.
BNut the very best recomendation I can make to you is buy this book if you have CS3.
TinyURL.com - shorten that long URL into a Tiny URL
It;s half prioce atthe moment and an incredible deal right now. Also, it's simply thebest book you can buy to leanr after effect anyway so it;s good value whatever the price.
If you need more specific links then PM me as I'm not going to blatantly post links to other video forums in the open.