Ofoto crops to correct aspect ratio.
http://www.download.com/3000-2192-10045231.html
Paint.Net is the free photo editor I use (needs the .Net runtime, but I had it already since I use Vegas Video)
http://www.eecs.wsu.edu/paint.net/
Also, there is a nice version of GIMP that mimics the photoshop interface. It's called GimpShop.
http://www.gimpshop.net/