Can Wi Fi be routered to 3 desktops without Mi Fi?

I am in a good coverage area for AT&T but not verizon or sprint of which are the only two places that offer Mi Fi. So did some looking and it seems there are routers that accept either a usb receiver or a pc card. So my question is, if I got an AT&T wi fi is there a router that would allow me to connect 3 desktops to it to use the single wi fi? If so what kinda router am I looking for (name or key words to look for in that kinda router). Or any other imput would be great. Thanks.