. . . in fact, I'd strongly recommend that book (Drawing on the Right Side of the Brain) to anyone else who wants to learn how to draw, or draw better.  I don't want to be long winded but there is a genuinely startling exercise where you draw upside down and end up doing a better job!  It's fascinating stuff.  At the moment it's my favorite drawing book.  Funny you mentioned it, Owl :)

Since we're plugging books now might as well plug a little software :)  For all around quick and easy drawing/painting take a close look at SketchBook Pro 6.  Only $30 or so at Amazon and just a really well designed and easy to use product.  Lot's of good Youtube tuts from some really good artists.  One of those softwares that's just too good to pass up for so little money.

And then there's the Rolls Royce of paint software:  Corel Painter.  It's great fun and amazing.  After much confusion about price (I couldn't justify the $350 at Amazon as a mere hobbyist) I called Corel on the phone, we bickered a bit, and I said, "I'm sorry but I'm just a hobbyist.  I can't spend that kind of money to finger paint."  the guy at Corel said, "Well.  the lowest I can go is $149."  So, I said, "Cool.  that's fine.  I'll buy it."  I was quite surprised to find that they would negotiate price with a mere, but persistent, hobbyist.

And finally, the one bitmap/vector software I would buy if I could buy no other . . . drum roll:  Manga Studio 5!.  Too much to type.  Just buy it.  It's wonderful and there's nothing else like it.  You don't have to do cartoons.  It's a great bitmap/vector painting app and a steal at $80 or so.  For me Manga Studio 5 is that "once in a decade software discovery".