Graphic editing is one part skill to one part tools.  A good graphic editing tool in the right hands can provide stunning results.  If you would like to get serious about editing images and creating original graphics, you need the best tools.

Adobe Photoshop - Adobe Photoshop is probably the most popular graphic artists tool.  You can do basics such as cropping and resizing, but you also can do layering and effects.  There are fill techniqes, gradients, lasso tools, lines, shapes, and much more.  Photoshop is intended primarily for modifying graphics. 

Corel Draw - Corel Draw is part of a good line of graphics related products from Corel.  These products include Corel Paintshop Pro, Corel Draw, Graphics Suite, and Corel Painter.  Corel has been producing great graphics products for years.