I've got Photoshop, which is overkill, but it works. I've also got Adobe Phote Deluxe, which is much easier to use, and has some great features, like red eye reduction, that I haven't figured out how to do with Photoshop yet.

My camera (Nikon) came with some basic software to do sizing and printing, but it isn't adequate for some of the manipulation I want to do. Specifically, it doesn't give you a good way to manage the basic size of the image.

Photoshop gives you the most strength but it's most expensive. Photo Deluxe will probably be a good fit, and it should be findable for cheap.