Personally on mac my favorites are Safari then Camino, Firefox and Mozilla in that order.
On PC: Firefox, Opera, Mozilla, then IE and its derivatives.
Of course to a newbie, your best bet is Firefox for security and usability. IE is to avoid except when really required IMO.
The mozilla app actually is pretty much outdated Firefox, NVU, and Thunderbird combined. Mozilla can do everything, it is just that good at everything
I also recommend Thunderbird over OE, as Thunderbird is as capable and much less prone to virus attacks that target OE.
Ciao