Do not waste your money on the Airport Extreme (g) base station.
It costs way too much, and it doesn't act as a hard router (RJ45 cables - as well as wireless). I believe it only has one port for LAN? It's been a while since I used it, but I wasn't impressed by it - considering the price.
The good news is, that it's officially supported by Apple - and of course - integrated and easy to use.
The bad news is, you pay a $200.
Personally, I don't think it's worth paying that much anymore. Wireless routers practically come in boxes of cereal these days.
Also, avoid anything by 'Buffalo Technologies' like the plague. I used some of their wireless technologies (not by choice) and they were awful.
Instead, look into a Belkin, Microsoft, Linksys or D-Link router. These brands all act as wireless routers, but also - include the ability to plug in computer without wireless cards into the unit to connect via the ethernet cables.
If you shop around, you can usually get these units for free, or for $30. I got all of mine for free, luckily.
Make sure your router is an '802.11g' router. The 802.11b routers are cheaper, but they will not be as fast.
Don't worry, just because it doesn't have the Apple brand on it, doesn't mean that it won't work. They all work just fine with the macs. Just make sure the router has a web-admin function. I'm fairly certain, they all do.
I run a Belkin and a Microsoft router (on top my Linksys). All of them have web-admin tools which are quite easy to use (although, I must admit, the Microsoft router has the worst UI out of all of them).
Don't believe the hype - the Airport base station isn't that great. Look for a deal on a wireless g router and you'll be fine. Remember to read the manual so you can learn how to set a WEP key and whatnot. All it takes to set up is a bit of common sense really. It's rather simple.
Buy the Airport if you've got cash to burn, and if you're deathly afraid of having to think for five minutes, as well as reading a few pages from the manual. Otherwise, any Wireless G router should do you nicely.
Good luck.