Photoshop is industry standard and has everything a designer needs to work with graphics of all kind. Therefore the application itself is huge and hundreds of addons are availabe. The Corel X5 suite on the other hand (my favorite) has all the features you might need (Photopaint and Draw) but without being bloated like PS.
Both softwares have the ability to export your work for a printshop (fonts, color separations) or for the web.
If you are a beginner, I recommend Corel, if you want to enter the graphics design business, there will be no way to live without PS.
One important issue is the price if you are not a torrenteer - Corel will cost you half the dough than PS.
I recommend to check out Lynda.com for Video tutorials, I tried myself and learned a lot despite the fact using both apps since years.
All my websites graphic work was done entirely in Corel
http://alexxis.euI hope I could help you in your decision...
Carpe Aptenodytes!