Best way is to use the Migration Assistant. We use it at work when doing upgrades. Easiest way is during setup, or afterwards as long as the name is different on the new computer. Otherwise it'll ask to overwrite your new account. If that's too much of an issue, I recommend the Target Disk Mode anyway. It's easier IMO than going across the network. There's nothing to setup, the old computer will just show up as an external hard drive. If you already have a network, and they're both able to connect to it via your router, then you can enable sharing in the system preferences if it isn't already. Then just connect via the Finder.