How do I connect an iMac w/ Wifi to a Mac Mini?

We're set up with Wifi at a temporary RV location. My wife's iMac is set up with Airport for Internet access but my Mac Mini is not. I tried to connect the two computers with an ethernet cable and to set up the configurations through the Network Preferences, then "Sharing," then "Internet." I didn't manage to get Safari working on the Mac Mini and I somehow knocked out the Wifi connection on the iMac at the same time. Does anybody know the right settings to get the Mac Mini to "network" with the iMac so we can use both computers and the Internet at the same time? Thanks and much appreciated.