Animation is the difference between boring and cool. I spend 10-20% of my time modeling (makeing stuff). 10-20% of my time playing with the colors (palette) and most of the time animating. Not that I am some great expert, I've only made 4 total.
I did a fairly simple unit first, then got more complex. Stay with simple hard-surface units (vehicles) to start with. Pick stuff you like. It is more fun that way.
OpenFX is used by alot of people, so it is no doubt a good place to start. I know several guys who are star wars fans are just getting their teeth into this.