Hi Anthony,
Other things that can be manipulated as well, this may depend upon the software that you use and what version of that software. As an example, If you have Photoshop CS3 or CS4 you can adjust sharpening, color saturation, and so forth, in addition to what Ian stated.
As far as post processing software, I think most people use some version or form of Photoshop (CS2, CS3, CS4, or Essentials (the light version of Photoshop)). There are others out there that people use, and I'll let others mention them as I'm mostly familiar with Photoshop.
To quote Photoshop CS3 Help with regards to RAW :
A camera raw file contains unprocessed, uncompressed grayscale picture data from a digital camera’s image sensor, along with information about how the image was captured. Photoshop Camera Raw software interprets the camera raw file, using information about the camera and the image’s metadata to construct and process a color image.
Think of a camera raw file as your photo negative. You can reprocess the file at any time, achieving the results that you want by making adjustments for white balance, tonal range, contrast, color saturation, and sharpening. When you adjust a camera raw image, the original camera raw data is preserved. Adjustments are stored as metadata in an accompanying sidecar file, in a database, or in the file itself (in the case of DNG format).
When you shoot JPEG files with your camera, the camera automatically processes the JPEG to enhance and compress the image. You generally have little control over how this processing occurs. Shooting camera raw images with your camera gives you greater control than shooting JPEG images, because camera raw does not lock you into processing done by your camera.
To shoot camera raw images, you need to set your camera to save files in its own camera raw file format.
Hope this helps.