its harder to use a usb wifi dongle though, because linux does things with usb that interfere with it. instead get an add in wifi card with good linux drivers, it will work better.
I've had reasonable luck with OpenSUSE and my usb wifi dongle; hardest part was realizing that the OS just wasn't starting the network manager, not that it didn't have the right drivers. Too scared to try it on any other distros though, definitely wouldn't want to deal with it during a Gentoo installation.
Personally I'm of the opinion that for power/normal computer users linux systems are great if you've got plenty of free time or you know exactly what you'll get out of using it. Even once you've gotten everything set up the way you want it, I find there are usually more gotchas that'll harass you much more often than in windows. None are really computer breakers, but they'll take a little time to look up and fix. I started off with Arch on a spare computer second semester senior year of high school and it wound up doing nothing but sitting next to my windows computer running irssi all the time. The following summer I installed Debian on my primary desktop and IMHO it was a great move. Familiarity with linux systems definitely payed off at uni both for classes and work. I currently dual boot with windows 7 for games and media usage. Even my netbook dual boots, but that's just because I need software for lab work that only runs reliably in windows and I have Debian because it's nice to have an OS that my hardware meets the minimum requirements.
But if you're a casual user (ie all you do is surf the web, word processing, etc) Linux
could be good. If you can get someone to set it up properly for you, 90% of the time you won't really be able to grasp the differences from windows/OSX. I've found the single worst thing about linux for this purpose is how Open/Libre office handle conversions from MS Office power point presentations; it's always just really damn garbled. There are probably other issues, but they aren't big enough for me to have noticed yet.