This is a good one. Free too!
It's a lightweight portable program, so it won't strain your system. But it has all the cropping and resizing tools you need.
It also has good color correction tools. That means things like levels, curves and hue and saturation controls. All the controls are very similar to Photoshop's tools. So if you've used that, you should have no problems using this program!
Note that this is a portable program. Some antivirus programs will falsely flag it as malware. It is safe to run.
interesting find, thanks! I'll check this one... great alternative to photoshop for people who cannot afford the expensive suite. also, not everyone needs the full set of tools that photoshop provides.