SuperDuper
Which is the best way to transfer all my data onto a MacBook Air?
Can I use a time machine backup and use that to transfer information, or would I need to use wireless migration assistant?
Since I regularly backup all my MACS using SuperDuper (producing a bootable image copy on an eternal USB drive), I just plug in the appropriate USB drive and migrate from a local volume.
Its VERY fast and reliable. Unlike the horrid Wireless migration, or the only slightly faster network migration.
If you are a TimeMachine user that works well too from a migration perspective. My experience with TimeMachine is that it does not back up everything, is brutal on system resources when its running, and incredibly rude on portable machines every time you plug in or connect to any HD. I've simply removed it from my machines.