Oh, you are going to have so much fun! Congrats!

Yes, I have known many people who have purchased the D50 and D70 in the past. I'm assuming the D80 is the new model for this year. I also know someone who has upgraded to the D200 all with fantastic results. When you are looking at the SLR range of cameras, Canon and Nikon are almost equal. Usually it's just the photographer's preference which makes them choose one over the other.

It's great you are also taking a photography course. The course will provide more indepth information on your camera and will allow you to practice with all those extra features. Enjoy! I'm looking forward to seeing future photos.