add the honey at flame out at the end of the boil.
How much hone you ad and what size batch will determine how much (more) yeast you might need. If the added honey will take you above 1.060 OG you might want to use more yeast... I.E. two liquid pitches or two packs of dry yeast.
if brewing 5 gallons 1 lb of honey can add a nice amount of honey character. Type of honey can make a big difference as well.
good luck!