Zebediah Magus said:I don't believe you should bother with supplements if you're starting, since the core rulebook is very complete. Once you and your gaming group are confortable enough with the rules you can try to customize with books like Ultimate Power or Mastermind's Manual.
I'd actually recommend Ultimate Power as the first supplement. At least on Atomic Think Take, it's referred to more often than the Core Rulebook when questions arise regarding how powers work. I picked up both Ultimate Power and the Masterminds Manual. I like them both, but I don't really need the Masterminds Manual (since the rules as written work well for the game I want to run). Ultimate Power, however, will be there along with the core book at every session.
That said, the core book all by itself will take care of you just fine. Ultimate Power adds a lot of clarification and touches up some powers that had problematic elements, but it's not required by any stretch.