Sometimes there are signs right after you pass the guard house. It usually says something like "Hotel Entrance/Valet Parking". IN any case, pull up to the front of the hotel and tell one of the CMs standing there that you would like to valet park. They take your keys and give you a receipt. Since you are staying at the AKL, they will charge your room $6.00 each day it is in valet parking.
When you take the car out, the valet parking CM at the AKL should give you a sheet (he may already have put it on the dash) saying you have already paid for valet parking for the day. You can then valet park at any/all Disney resorts and it is free (costs only $6.00 for the whole day any resort) Not sure if it applies to DTD.
Depending how busy they are, they are usually pretty quick in getting your car, average wait about 5 minutes.
Tipping. Well that topic stretched a thread a while back to 5+ pages. Some people tip $1-$2 when they drop the car off and $1-$2 when they pick the car up. Some tip $1-$5 only when they pick the car up. On a recent trip report thread, the person posted that he tipped $10.00 (accidently).
Ed