Title thread says it all. As I am getting into a more serious approach with After Effects I feel the need to do more than just a bunch of simple effects that I've been doing till now:

Rotoscoping (lightsabers)
Simple Greenscreen / Bluescreen effects
Color Correction
Noise Removal
Aspect ration conversion (4:3 to 16:9)

I want to know all the basics on how After Effects works, but I'm not sure where to start.

Any ideas?

AF isn't really that great for rotoscoping in my experiences. I would opt to use Shake if you have a unix option. Shake is older but at the moment I've found it to be far more robust in terms of usability.

Same goes for green/blue screen operations. They can be done in AF however it's not the best choice.

Color correction can be done very easily by right clicking on footage in the time line and clicking effects > color balance or something simple like that. Noise removal is pretty much the same process as above. Think of it like a photoshop filter.

Aspect ratio coversion can be done quite easily by manually resizing the footage. Just make a new composition in the size you want, and resize or crop your source accordingly when you import it. You'll always have to crop if you're changing from 4:3 to 16:9 depending on how your footage was shot. It's not the best idea to convert from one to the other.

A quick google search will bring up all the answers you're seeking. Try "video co-pilot" for some more advanced stuff.

As for going on a course, almost any visual effects course should teach the above and more.

Video co-pilot is a great resource. I havent used shake, but it's definitely something you should look into

[double post]

The real thing to remember though is that no matter how good you get with AF, it'll be my shake that brings all the boys to the yard.

If you know photoshop, AF becomes familiar after a few tutorials. I just recently delved into it, and it's a lot easier than it first seems.

I've been using GIMP for a long time, so photoshop isn't too hard to get used to. I've never used Shake, but unfortunately unix/linux isn't used very much around here, so I most likely will have to with a windows option. Seeing as most people use After Effects here. I am open to these options, but I have to learn one system before I jump on another.