I think Baltwo has a good solution - particularly if you are uncomfortable with the computer and system, etc.. I hadn't thought of the Snow Leopard step but didn't have Snow Leopard anyway.
I simply connected the new computer (a MacBookPro) with Mountain Lion to the old with Tiger by my home ethernet and transferred all the files, music, pictures, and settings. Setup assistant is not that critical. Simply open System Preferences and go through the various settings one by one. Most of the applications will not run on Mountain Lion without updates/upgrades and are better reinstalled.