Debby - Adobe Photoshop is a real expensive program, about $600 I think.
However, there is a pared down version called Photoshop Elements that is only about $99, but there are also offers for rebates, etc. I've seen it as cheap as $50 with manufacturer's and instant rebates. It has most of the same features as the big version, except some of the real advanced graphic design features like designing animated pics.
You can download a 30-day trial of Elements for free at www.adobe.com.
I absolutely swear by either of the Adobe Photoshop products. They are pretty easy to use, and you can do almost anything to your pics!