As far as sheilding, it is normally much more important to shield the pickup cavities first, with copper foil etc. Then a wire should be soldered to each shield and taken back to the middle wire of the jack which is the ground on the standard Switchcraft jacks I use.

There is normally a black ground wire and a green wire from the retro soldered to this tag on the jack. (Do not connect to the single black wire from the battery, or else the pre is likely to be powered continiuously)