Well, if you fancy Photoshop, I can send you one of the manuals I hand out to people I train on it, it has numerous tutorials in it and is a lot less daunting than the Adobe ones that come with it, which are enough to send you to sleep. Let me know if you want one.
The nice thing about Photoshop is that you can animate with it and export to Flash, so it's good for web stuff as well, which is worth bearing in mind when you consider the price, as it is a lot more than just a program for tarting up pictures, the most recent (CS3) version has much improved selection tools and is also optimised for doing stuff like creating screen animations for mobile devices.
Photoshop may look complex, but bear in mind that all software like that looks complicated when you first see it, but closer inspection reveals that the menus are laid out in a very logical fashion, and to be honest, a lot of it is simply twenty different ways to skin a cat, which is what people find out when I train them on advanced courses in it! Also note that much of the stuff in there is for repro (probably a good fifty percent of the stuff in the program in fact), so you may never have call to use it if you are not producing artwork for print.
Photoshop's CS3 incarnation has seen a decent change to the contrast controls which might prove of interest to you if you are having problems with grayscale images, Adobe have placed intelligent limiters on the brightness and contrast functions so that it is a lot more usable than it used to be, and it is kind of hard to screw things up with it now, although you can put it in 'legacy' mode and have it work like the earlier version if you so desire (this is a bonus for me, as I will now be less likely to come across students who are using the levels and curves for the wrong thing - LOL).
However, this is a good alternative if you don't want to cough up for Photoshop:
http://www.getpaint.net/
Chock