well if you don't care about the debian policy you could always add contrib and non-free behind 'main' in sources.list that way you get access to all the packages maintained by a debian member. for me installation of media stuff is done as I go, as soon as I notice i'm missing something I'll install it. (adding non-free will also allow you to install macromedia flash plugin and Sun JRE and things like that)
about your wireless card, check with the command lspci what kind of card it is, who's the manufacterer, what type is it?
This is the relevant output of my lspci command (assuming that you have a pci wireless card).
Code:
02:0a.0 Network controller: RaLink RT2500 802.11g Cardbus/mini-PCI (rev 01)
This shows all the relevant information, after that you can search this forum or google as to how you can install it.