lol.. i'm gonna assume you have a wireless router...
if you have cable/dsl, you would connect your cable/dsl modem to the router, and after that everything connects to the router. your laptop will connect to the router. your desktops should connect to the router via wire, wires are better than wireless...
your router should have at least 4 ports for connecting computers via wire.. all new computers have built in network cards (aka NIC cards..) if you have an old computer, you may need to buy the NIC seperately.. which only costs a couple of dollars...
so:
modem >> router >>>>> all comps