I usually go for a canvas from Michael's or some other craft store with a wooden frame in the back so I can hang it on a wall if I please. It doesn't even have to be expensive. In fact, Wal-Mart has nice canvases.

An easy, workable paint for beginners that looks nice and stays nice is acrylics. I prefer Liquitex Heavy Body. (The Liquitex Basics, although more friendly on your wallet, I do not really care for. They have an odd texture in my opinion.) You can find it at JoAnn Fabrics or Michael's and most craft stores.

When I paint, I have a shop rag with me, and if I make a mistake, I wipe the paint off. To me, it is effective, because I'm the type to just re do the section if I need to. However, other ways, such as paint thinner, I have never tried.

And if you work with charcoal rather than paints, you can preserve it on your chosen surface with matte finish spray. It's in with the artist sprays at the craft stores. I have a can of Krylon Matte Finish that's saved me many a time.

Any other questions, feel free to ask me. :] Good luck.