bodywork preparation

[sideways dan]

posted this in the griffith section but thought i may get a better response here. took the body off the griff due to absolutely rotten outriggers, so i've decided i fancy a colour change as part of the refurb/rebuild. i would like to do most of the preparation before painting myself and was just after some advice on the steps one would take to do this, ie grades of sandpaper, how far to take the paint back etc. the bodywork currently is fairly good to be honest apart from a 'chunk' missing behind the griffith badge which i assume would just be remedied with a bit of filler?? thanks in advance chaps, dan