[Mark Sir Link]

Finale if you're really serious about it, NoteWorthy is also pretty decent.

as for inspiration, just take a look at the some "top 10" lists or something about video game music, and listen to them to get a kind of feel for what's appealing.

If you're interested in Video Game music specifically, I would suggest in no particular order

Mother series
Zelda series
Mario series
Final Fantasy series
Warcraft series
Donkey Kong series

and I'm sure there are several more