Paint advice

I need a little advice on primer. I have started sanding on my 73 Dart Sport which has some areas of surface rust. It is coming off fairly easy with 100 grit. I have decided to take the car down to bare metal. I would like to know what the best way to prep the metal and what would be the best primer to use. Keep in mind that this will be my first paint job. I've let it scare me for too long and I'm just jumping in and going for it. Thanks in advance for the help and advice.:coffee2: