Can I create a banner ad on os x? (Free)

[steve111]

I need to create a banner and was wondering if there was a way of doing this free? (And ideally something easy to use?)

I'm not sure what I need exactly.

Software to edit a picture (add text/simple changes)
Software like word (where I can add different styles of text)
Software to create a good banner (importing pictures ect.)

 

[r.j.s]

Gimp is free.