Which version Xbox 360?
The new "S" (Slim) one, or an older Core/Arcade/Premium/Pro/Elite?
The Xbox 360 S (250GB & 4GB) has WiFi b/g/n built-in, the older versions do not.
If it's an S, you're sorted. Just connect it to your wireless router.
If it's older, and you want to take it wireless, you need an official Wireless Adapter (£££), or you need some sort of Wireless Bridge. Can't just use a USB WiFi dongle thing.
If you end up being stuck with going via the PC, you should be able to get it online using Windows 7's internet connection sharing. I've not used ICS since the XP days though, & can't remember how to set it up.
MS have instructions here however:
http://support.xbox.com/support/en/u...onsharing.aspx
Once connected, sharing media from the PC to the 360 is easy using Win 7's built-in facility (WMP12 and/or WMC), or using free 3rd party software such as
TVersity or
PS3 Media Server (despite the name it does a good job for the 360 too).