How to share files between two Macs at home?
I guess your question is how exactly do you share files. To access the shared files just:


While in Finder select Go > Connect to Server... or hit Command+K.
A window will appear, prompting for the Server's URL, which is the File Sharing Computer's network IP, something like 192.168.1.2. Before the URL you must write afp://. So, it will look like afp://192.168.1.2.
The other Mac's sharing folder will be mounted on your Finder. 


Just so you know, when you enable the File Sharing, beneath the green light, the exact URL of that computer will be shown. The afp://your.network.ip.numberthingy. 

If you are using Lion, or later, Airdrop is, by far, the best option for file sharing. It requires no setup nor special settings, and it sends the files wirelessly, without having both Macs to be connected to the same Wifi network.