To be honest, I haven't been to the training arenas yet and I've been flying for a week and a half. I prefer to go straight into combat and learn as I go along. Of course, I'm also building a very large training manual that I keep in a 3-ring binder and I try to read a few pages each night whether I fly online or not. Poking around here and at
http://www.netaces.org has helped immensely.
I flew AW 1.5, AWII, AWIII, and AW Millenium Edition just before EA dropped it from their line-up. A lot of the concepts I learned there are transferrable to Aces High, but my biggest problem is just learning the key commands for the aircraft, radio, etc. and learning the flight model.
Since you're coming from CFS1, you probably have a pretty good idea of gunnery and ACM, but now you just gotta get in the stick time and learn the systems. You also gotta get used to the idea that you're going to get spanked now and then by guys better than you. Just keep flying!