Replacing bearings, spokes etc. I leave to the bike shop. These are jobs that will only frustrate you and could leave you stranded halfway into a race if not carried out properly.
Setting brakes and gears I do myself. These are jobs that need to be fine tuned as you go along, especially the gears. I find that bike shops set gears and then don't test them properly by riding the bike for a few km.
Is this for your Bianchi, ewep? I have posted some nice Campy service instructions elsewhere on the board.