Hi,
Take it slow and don't get bummed if you can get it like you want. It takes time - but before you know it - you will develop a style that works. From there, you can build.
I would highly recommend you use Photoshop. Almost all version that are fairly new will be the best tool. I think anything from 6 up will be great. I personally have CS and 7 - but tend to use 7 more. Who knows why.
Then, just practice. Maybe make a background. And then just start playing. Adding text and maybe mix some images...just do something. from there..you will stat to get the hang of where things go and how things work. But - don't be afraid to experiment. Maybe start with a 1024 X 768 image at 72 dpi. From there...just go to town and use some of the filters. You will slowly develop some ideas on what looks good and what doesn't. But keep with it.
I am sure you will have fun. And if you can get photoshop - learn it. It is one of the very best tools out there. I really can't see any program replacing it yet.
Hope that helped. Enjoy.
freelight