there are plenty of sites with photoshop tutorials. learn the program now as you'll need it in the long run. if you aren't willing to learn such a fundamental system you might want to reconsider getting into this business.
I use paint shop pro. I think it's fine if you're not really a designer(and may be fine even if you are). But if you want to get good at graphics then just start learning photoshop, since it's the standard.