I drank lots of water a couple of days before and several days after (actually, I STILL drink more water than I used to!) I stayed flat for about 2 hours right after, then got up and drove home (if you get valium or such they probably won't let you drive yourself home).
I was fine that night, but made the mistake of bending over to pick up after my puppies. Got "the" headache 24 hours later, had it 4 days until I finally spent a day in bed. SO: DO drink lots of water/juice. DO stay laying down as much as possible for 24 hours after. DON'T bend over for a couple of days. You'll do fine!