I think a tablet is always a good thing to invest in if you want to try out more digital art.
However, there is a way to solve your problem I think, if you don't mind pencil lines mixed in with digital coloring haha (a lot of people do this for their sketches and what not)
You can scan your pencil image, open it in SAI (or whatever program), adjust the brightness/contrast to your liking so that the outline and background can be darker or lighter, and set it to "Multiply" - that way you can color underneath it. :0

Thank you very much, I would like to prefer doing my work in pencil then do digital coloring. This should make uploading work faster since re-outlining is not a, fun thing to do....especially when the lines don't look as straight as how the sketch looked which...would make the work not as good :_;

I got some help with a friend about the multiply bit since I was confused by what that is.

Also, thanks for responding back to a journal of mine. The main reason why I don't put journals on that much is how people don't leave any comments about it .-. So yeah, thank you ^_^

I'm gonna try this method out, and see how it'll look in the end. Thank you very much (I know I'm saying that a lot here .-.) I really appreciate it.