New 360s Owner Here, Any Advice?

[Millenium]

Dust it off once in a while.

Install your games to the harddrive.

Don't be cheap, and buy a gold subscription.

Look around for some advice on the best games.

Console orientation doesn't really matter, despite what people say, thought it wouldn't try any tricks to put it on a 45 degree angle or something :p

Don't move it while a disc is spinning inside it!

Use your own common sense, and you'll never regret having bought the console. :)