It's always nice when new people come around and actually are interested in learning instead of dabbling with their own attempts first and not really progressing. While the advice that may be given from time to time may seem intimidating, it's generally pretty accurate. When you've finished a piece, be sure to look back and note any mistakes. Remember those mistakes and be sure to not do similar ones in the future.
For just starting out, Gimp is probably going to be a great program for you. It's basic and is free.
It can be found here:
http://www.gimp.org/After getting used to the tools and options, hands down the best option for you is to follow tutorials. There's a nice compiled list here:
http://forums.d2jsp.org/topic.php?t=48069527Do what is there, apply it, and then be creative later on.
While this guide was for Photoshop, you may still find some useful tid bits here:
http://forums.d2jsp.org/topic.php?t=57874419Best of luck and I look forward to seeing you around
