drew - if your serious about learning but have limited cash flow then you might want to consider a cheaper, older Nikon dslr. I just bought my brother, a novice but willing learner, a Nikon D70s for £175 posted and then picked up a Nikkor 28-100 AF lens off ebay for £45... that's £235 for a complete setup!! Okay they are second hand but come from a reputable commercial dealer on ebay and have a limited warrenty. Seriously good value for money. I played with the D3000 last week and found myself frustrated with it's limited capabilities once you had learnt the basics. The D70 and D70s are, imho, similar in fucntion and size to the D90 except for some obvious differences (lcd, os, sensitivity etc). Jeez, even the D40 is arguably better than the D3000.
I guess my point is that if your serious you shouldn't go buy a D3000 because it's a 'beginner' camera, you should do some more research and spend your money wisely
Read the reviews:
http://www.kenrockwell.com/nikon/index.htm
I did and ended up a happy bunny!
Oh and don't get me wrong, I don't hate the D3000, I just think they're a bit of a waste of money.
CH
Edit: Before I get flamed remember drew stated he's really into photography and wants to learn, if he had said he wants an all-rounder camera to take pics of all things general and wants additional lenses (albeit expensive ones) I'd say the D3000 is a perfect camera
I just think it lacks the ability to teach the user about cameras after a certain point where other, older Nikon cameras don't.