Maybe this will help you:
http://www.wi-fiplanet.com/tutorials...le.php/1451421
FWIW, I have my cable modem connected directly to a wireless router and two computers which both connect wirelessly to the router. That is to say, I use "infrastructure" mode, not "Ad-hoc."
My PC runs Linux and wifey's laptop runs Windows. They are both set up to for file & print sharing through the router. I can easily browse file shares from either one. Under Linux, I had to set up Samba in order for Windows to "see" it. I had originally set it up so that my wife could print to the laser printer which is connected to my PC, but I have since added file sharing because it was trivial to add and very handy to have.