This what I use for anything since I can't afford a commercial product's.
http://www.getpaint.net/
Plug-ins list I use with B.G.M and anything else even my avatar:
Alpha Mask:
Pyrochild:
Edharveys:
Curtis:
MadJik:
Shape 3D:
Borders and Shapes:
Align Objects:
Drop Shadows:
Tutorials how to's forum:
And the patience and time to experiment,there times I gave up then come back again.
Sometimes during the tutorials when I'm between steps I discover something and start experimenting with certain steps,then of sudden some ideas come to my head and it will do to you too.
I'm no artist either,heck B.G.M V1 was my first to do anything of advance editing.
P.S
If your using Vista 64 or maybe window 7 64 bit,to be able to see the thumbnails for the TGA files you will need to install the DX SDK.
Link