[Butz]

You mean just the PNGs and stuff?
Well, Paint can do it, but well, it's Paint.
Photoshop will work, but sometimes it's overkill for the kind of stuff that you want to do.
I myself use a nice little program that comes along with a free online game that I won't mention, mainly because it has the 256 color palette all laid out unlike Paintbrush. With similar colors near each other. It only saves in BMP, but that's what something like Irfanview is for, to paste it in, then save it.