[llama64]

You'll have to relearn all your productivity software, and you'll have to relearn all the keyboard short cuts. In addition to this, you'll need to relearn the basics of window managment as there are significant differences between how windows behave on both OSX and XP/Vista.

If you're not willing to put in a few hours to retrain your muscle memory, don't switch. But if you are, you will probably (IMHO) find a much nicer work environment then Windows XP/Vista.

Newer Macbooks (aluminum case) use the "Mini-Display Port" instead of DVI now. Be sure you buy the correct adapter for your Macbook.

And keep your standard PC mouse. Trust me, Apple can't design a good mouse. It's beyond their engineers.

If your Telus setup is anything close to normal, then all you should need to do is connect the Macbook to your network and it will work without any effort on your part. If your setup is atypical, you'll need to call Telus.

Typical: phone cable from wall to modem, modem connects to router using network cable, computer connects to router using network cable or via wireless connection. (Telus has modem/routers now, so it's possible you only have the one device, in which case ignore the second part).

Peripherals:
Consult the manufacturer's website/documentation to find out if the device is supported on OS X. It is very possible everything will work just fine, but you will want to verify that before taking the plunge.