There are a few but depends on what you intend to do as a project, for overall use it's photoshop CS2 and up since it will pretty much do anything but has a slight learning curve to it. Illustrator is much tougher and usually you can find people wiling to share these programs but be aware that they are legit.
Gimp has it's limits but will also do many things with a different interface than something like PS, I've only been at it for a few years but it's a program that kinda hits you at once and it all comes together.
I use alot of online tutorials, which range from beginner up to extended.
You also need to see what your computer will handle in terms of creating images and applying layers that will make a file as large as 400megs when saving or opening in PSD formats like I use. Illustrator is smaller in ways but the same rule apply.
If you feel you are a bigginner, don't get discouraged, lerning to cut out an image with a transparent background should be your first experiance, then learn the saving methods like never using a .gif for transparencies since the quality is horrible, other examples would be in photoshop, saving as a PSD or a PNG are mostly what I use.
Programs like Jasc are a good start but again, knowing layers is the trick. Once you figure out the layers you should be golden in any program.
This was my starting point for the 34 for the contest but again we all have our ways of doing things, like creating your own XYZ for light and I add one for flash to look photographic on a seperate layer.