Joel Fagin's tutorials.
http://www.between-worlds.com/tutorials/The other tutorials are found in the dropdown menus at the bottoms of the pages. Brilliant tutorials, I've learned a lot from this guy.
As for your painter problem, I'll try to help though I don't own the program. Here's a couple of questions:
1. Do you have a new computer?
2. Do you have a really outdated computer?
3. Have you rebooted the computer?
4. Have you contacted Corel about this problem?
1. If you have a new computer, there may be an OS confliction with Painter. In which case, download the new drivers.
2. If you have a really outdated computer, it may not be able to run the newer Painter with as much grace as a newer one. Old computers have a tendency to run a program fine for a time, then randomly blow up and say it can't run it. If this is true, you might never be able to run Painter without serious upgrades or a new computer.
3. Rebooting is often the answer to every problem. If you haven't rebooted the thing, do so then try.
4. If none of the above helped, contact Corel. They'll certainly be able to help seeing that they have a trained tech department whereas I simply fiddle with school-issued computers in the hopes of making them better.
I hope this helps in some way.

And good luck with fixing the program.