depends on how far you want to go and whether "correctness" is of any concern. of course you will want to remove any signs of rust and treat the bare metal to prevent any in the future.. http://www3.telus.net/68bird/rust_repair.htm
many people put down some sound deadener while you have the seats, console and carpet out. it does make a big difference with road noise, heat, rattles, and sound quality in the car. http://www3.telus.net/68bird/sound_control.htm

be careful ;-) sometimes full restos start from simple beginnings..