I'm sure you'll find a lot of helpful people here if you have any questions. One nice thing about the Macs is how quickly you can put them to sleep and wake them up again. I rarely shut down my iBook or tower.
One tip: it's best to wait a few days after software updates come out before applying them. Sometimes problems show up on certain configurations and I prefer to let someone else work out the bugs first. You can get a lot of information on macintouch.com and macnn.com