request help

HI I just got a 68 vw bug and its a new project from end to end. Im at the stage of getting my stuff together and finding out what to start off on. Im done with makeing the shell ready to be painted and the chassey is ready to go. The shell and the chassey are ready to be put together. However i am wondering what would be my best NEXT step. should i start off on the elec. system and heating system? or should i 1st put the shell on the chassey? then do the elec. work? should i get it painted before or after the elec. system...? any help would be good thanks,...