Wireless to eathernet or wifi? before the connect to the computers?

Hello, I have a Wifi antenna with a built in adapter and a linksys wireless
router. How can I connect the antenna to the router and have 2 computers
connect to that mess? I have to have the antenna because of distance issues.
The other end or the main computer is Running on dsl connected to an
Actiontec wifi modem router where I get the signal. I am having trouble
finding the way to change the IP add. on the linksys on my end. I plug the
antenna/adapter in to one computer on my end and have no problem,but I cannot
connect the other? Hard wired or wifi. The connection will shut down the dsl
on the other end? And I cannot find a way to change the security settings on
the linksys either? It seems to be set on wpk and the computers wont all run
on that setting? I hope that is'nt to confusing? Any help would be
appreciated.