Just connect the two Macs with a Firewire cord. You might need a 400 to 800 adapter if your old Mac has 400 only and the new one has 800 only. You could also start with a brand new install and then copy your iPhoto, iTunes, etc. library over from an external hard drive.
Sorry I don't have expertise on any other way to migrate.
Home: 2006.5 iMac 20"
Me: 2010 MacBook Pro 13", iPad Mini Wifi 32GB Black, iPhone 4 16GB Black
Wife: 2011 MacBook Air 11.6", iPhone 4 16GB White
Are you backed up??? If so, why? Psyllium Fibre is not free but will do wonders!