need schooling on timimg

hi guys

ok i have a 340, j heads, 1406 edl, edl340 intake, mild cam, elec. ignition.
i want to do this from the carb. how many turns on mix screw to begin and what should i set my timing. do i need to plug vacuum when timing. the engine was rebuilt doesn't even have 200 miles on it. can somebody just give me some schooling. i cant figure this out, i am an air head when it comes to this. any info would rely be appreciated. thanks