Also have a look at the following links (if you haven't already), as the information presented there might be helpful in your future endeavours into Mac OS X and could clear up initial confusion and may even prevent harm to your system or your files.
Mac OS X Basics
Switch 101 - guide with articles made by Apple on how to accustom yourself, after you switched to Mac OS X from Windows
There are currently, as of today, NO (ZERO) Mac OS X viruses in public circulation. That may change in the future, but for the last ten years Mac OS X has been void of viruses.
Gratz, I love my MacBook too, I've had mine since 2006 without any major problems (except battery replacement under warranty). Overall great and sturdy little computers. Max out your ram and throw in a SSD later on down the road!