I was taught pulling spokes inside (head on the outside), as they get the most stress, and if your chain drops behind the largest cog, the outer ones get chewed up. I believe that's the gospel according to Jobst as well. But then, some wheel experts differ...

What's really important is to build a wheel so that looking down through the valve hole you should see the Campagnolo logo centered up.

All of this is approved by the ASFE.