hello

what im gonna ask today is probably simple but im an idiot at networking so it aint simple for me, say i want to buy a home entertainment hub, like one of them xbox media center things (not xbmc, but a dedicated system) how would i go about it, do i need an internal network card or can i use one of them usb wi-fi usb sticks? (example nintendo wifi usb stick (but obviously something completey diffrent, hence *example*).

and aside from 1 end (the pc end) what about the entertainment thing, what would i need to plug in to that to allow it transfer stuff (like streaming video?) to the television?.

now aside from the home entertainment, my mum is thinking about getting a pc downstairs sometime this year, id like to share my adsl connection with her aswell so she can have the internet, but how would i go about that wirelessly? i havent got the slightest clue what id need, but erm it would need to be something simple, which i guess it would be judging by todays technology

so an easy to read explanation on my problems above would be appreciated, thanks in advance