As I recall when I built mine, I went roughly in this order (after putting in seatpost so stand had something to hold onto)
:
--Put on stuff that attaches directly to frame more or less working back to front (RD, rear brake, BB then Cranks then FD, headset cups).
-- headset bearings, fork with front brake, stem
-- Handlebar with brifters (I was swapping from another bike so brifetrs and tape were already attached)
-- Wheels with tires and casette
-- pedals and chain
-- Housing and Cables