If one does have a bash with Linux, Ubuntu is probably a good choice for the novice.
There are certain things which are encumbered by patents and hence cannot legally be distributed with Linux (usually media codecs etc..), but Ubuntu has a huge community which has put together a number of 1-touch solutions to get everything you need downloaded and installed, patents or not.
Aside from that you've got the usual excellent web browser (firefox), email (thunderbird), openoffice, and you can run a lot of Windows apps using Wine if you need to. I have a little Asus netbook and use Wine to run iTunes to sync the iPhone. Works a treat.