Don't listen to the MS paint comment. You're better off sticking with gimp because it's like photoshop. MS paint is a dead end and also pretty awful.
When I draw comics, my set up is:
Intous5 bamboo tablet | Before this I used a Bamboo Fun tablet which is cheap and works great.
Photoshop CS5 | gimp can substitute for Photoshop if you cant get photoshop.
I create a new layer (which you can do in gimp) and draw rough sketches of the comic I'm thinking of. I use that layer to arrange everything. Then I turn that layers opacity down so you can only just see it. There should be a slider for this in gimp somewhere on your layer options. I create a new layer, and draw more confident and clean lines over the faint sketch. Once that's done and I have all my lines, I turn off the sketch layer and create a new layer under it to paint in backgrounds, then a second layer to paint inside and under the lines I've drawn. To colour the characters pretty much. After that's done, I create a few more layers and add speech bubbles then write in the text, and sometimes I create another layer and give everything in the foreground a thick outline. Then the last layers on top are used to put my title bar over it and I'm done.
It's not a difficult process once you get used to it and it's a very professional way to draw digital comics. That is exactly how Mike Krahulik (Gabe) of Penny Arcade draws their strips. If you want to learn more, he does live drawing streams you can get to through their website, and you can watch an old video of him inking a drawing on his youtube channel.
http://www.youtube.com/watch?v=QNREP5l4xTw <- warning, video contains music with swears in it!!!
Edit: cleaned up the comments to preserve this fine threads original purpose.