Logo animation help

It's just basic roation and scale animation mostly. Literally any basic keyframing tutorial for AE can teach you that. And the logos theeselves pretty clearly are simply artwork prepared in Photoshop and Illustrator and then imported. I suggest you actually start by reading the online help. It's really not that complicated.

After Effects User Guide

Mylenium

I don't think I know of a tutorial, but it looks to me like a simple arrangement of layers behind the logo.  They are animating into their final position largely with rotation and a bit of scaling.  In a couple of the instances, there's some "growing" going on, but I think you could experiment with either the Liquify effect or the Bezier Warp effect to achieve similar.