picture program

There is a free one called gimp(GNU Image Manipulation Program) that does a lot of things photoshop does. There are tons of addons for it too that are free. If you take the time to really learn it Gimp is a powerfull tool. I use Gimp alonside Lightroom 3 on my Mac.

http://www.gimp.org/

Here is a blog from a person that really uses Gimp to do all of her photo manipluation. There are some great pointers on there too. The blog writer has some really amazing shots and she shoots with nothing more htne a rebel with a decent lens.
http://iffles.com/

You may also want to look at paint shop pro. I call it the poor mans photoshop. It does a lot of the same stuff and its cheap. Its on sale right now for $40 normally its $99. I have been using it for years. I bought it and used it on my windows pc before i knew about Gimp.

You can download a free demo to try it out.

http://www.corel.com/servlet/S...=tab0

Adobe also makes a cheaper less feature rich version called photoshop elements.