What is recommended procedure after Snow Leopard install?
 

I typically use Smart Update for regular backups. After installing Snow Leopard, is it fine to leave that as scheduled or would it be recommended to do a new Erase and Backup?

You'll want to delete and recreate your schedule, but you can continue to use Smart Update. That said, an erase after a major OS update never hurts (and can help clean up the backup drive's fragmentation).