I would give Gimp a 100% recommendation. I have been using it for quite a while now and find it meets all of my needs as a serious amateur. Much better than the limited Picasa and almost on par with Photoshop. Course it's free! There are several books out there for it and I now have three of them. The first two are probably good if you already know what you were doing. Not for me but will probably read again after I gain some experience for advanced techniques. The book I recommend is: How To Gimp by Kat Landreth. A google search will find it for you. It's also inexpensive as it's an ebook so I think it's $9.99 and well worth the price. Do be afraid to try Gimp as you have nothing to lose. Hope this helps. :-)