networking 2 pc's

[taffio]

Hi, Can anyone help plz ?
The problem is i have 2 pc's networked both can access the internet but i can't seem to play games on the LAN nor can i find any files on my network places( both pc's) i have set up to share the Hard drives but it does'nt seem to find them.
If i try to make another network connection i can share the files on both pc's but then i can't access the internet on the second pc.
so basically i get one or the other, but i want both.
i have had it set up before but had my pc setup again and now i can't seem to get it to share internet connection and the files.
.
Hopefully i will sound like a real noob and someone will put me in the right direction.

cheers