Well little write up to show you people how to connect your 360 to your pc and how to change your dashboard.
First up you'll need either the
wireless adapter or an ethernet cable which is shipped with the unit.
First off you will need to get the box on your network, not having used the wireless I can't comment on that I just plugged the ethernet cable into my switch and it was on the network i check Xbox live and it worked fine this ment it could see the net which ment i could see it.
To share thing with your Xbox like music and pictures you'll need a copy of
windows media connect.
Can google it or get it from
here its real easy and straight forward to instal, much like most of Microsfts software.
Once installed run it and then from then go into devices and check that the xbox is there and that it is set to allowed.
Next up you want to check that you have things shared that you xbox can then see on the network, it default shares your My Pictures and My Music folder as thats the default locations of music and images on all windows based machines. You can however add more folders to share and remove folders that have been default shared.
Next up you can now go onto your xbox and view and listen to what you have shared.
This is how you can view your images and set them as your background on your user dashboard also use similar steps to listen to your music.
First go to Media then scroll down to pictures and then to computer and then from there it will show you all the pictures that you have shared on your computer, there may be an inital setup required where you have to choose your computer from a list of machines but it will only show the computers that have the media connect software installed you can't just share things on an XP machine and have the Xbox 360 see it and view the content you have to have the 3rd party software running all the time.
Images below show you what to do

, it pretty much explains its self



Quick blurb from the Microsoft site
LINK if you are unsure still then visit the site and have a look around the FAQs or ask on here we have all the answers im sure.
Morgan.