1. make them up the same time as you do the invitations but send them out after the wedding
2. i don't use my surname in my signature so I signed in my usual signature
3. you will have to wait for your official marriage certificate from BDM (which you have to order & pay for - not the one you sign on your wedding day - well it is one of the ones you sign on your wedding day but you don't get to keep it as it has to be officially lodged) before you can change names on things - places will change your name on your bills etc for FREE (yes including licences - well in Qld it is free) - some places will do it over the phone with no proof (telstra is one), others just want to see the certificate and will take a fax. It took about a month to get my certificate from BDM. I am in the process of hungint down mine since we moved, I forgot to change my name on my ING account!