right.
1. wifi for 360 is expensive but worth it if you can afford like £50 or what ever they cost these days.
2. you can link it to a laptop via a cross-over network cable and share a laptops wifi connection to get on live! (or a desktop PC with a wifi adapter in place)
3. my preferred option would be getting a network extender adapters (i think they are called "Homeplug") that plug in to your power outlet switch (1 near router and 1 near 360) and this makes a wired connection over your powerlines.
Link:
competitor
altho i prefer the pair at £50 - Link:
competitor
because you still get the functionality of the plug and they are 200mb so i have mine plugged in to a small switch which connects multiple devices
if you would like further on any of these points
When it comes to audio, the audio will travel down the HDMI cable (if you decide to go down that route) or you can use the HDMI cable plus the original component cable supplied with the console and use the audio RCA (white and red plugs) to connect it to a different device (stereo) OR then buy a converter to change the 2 RCA plugs (white and red) in to a 3.5mm jack which you can then plug in to standard speakers.
any questions??

let me know if ive missed anything