I will need to connect to the DSL AT&T modem which has its own built in router and also my HP 8710 printer. Both are hardwired right now but the HP can only be set up one way or the other so the other users on the LAN can't access the printer (stupid change on HP's part from previous printers). Is there any particular info I need or can i just walk into Fry's and say 'give me a wireless card'?
Should be able to use most any wifi card compatible with your computer, for basic use. Heck, i use a D-Link 10 dollar wifi stick ever since my network card got fried a few weeks ago. Now, they aren't the best if your trying to do net heavy things like online gaming, but if all your looking for is connecting to the internet and browsing, videos, downloading, etc, a decent usb wifi adapter stick from any electronics store will do. Id suggest netgear though.
If your looking for faster than that, as in blazing speeds, it'd be a good idea to go with an internal, high speed card, though those are more expensive.