The Anfield event has a bottle hand-up service. You start by doing a dogleg, then do four laps of a circuit. You label your bottles with your race number beforehand, then half way round the circuit there's a guy with a walkie talkie. Shout your number to him, he'll radio the guy 200 yards down the road who will hand you up your bottle. Fill them with coke or something else sugary and they'll help you get round.
I did the Anfield last year as my first 100. Read the report
here. Also, see the map below. On the Anfield I started with two bottles (one coke, one water), four gels and two bars. I managed to drop a gel and ate all my other food and could still have done with a bit more, but then I'm quite slim and need to keep eating. I only got through three of my bottles though. I then started two more 100s last year, where I started with two bottles and stashed an extra bottle in the grass to pick up on a subsequent lap. The first (the YCF) was a complete fail, I wasn't rested enough and quit after 20 miles, so I never got to use the stashed bottle. On the second (the Team Swift) I ran out of food on lap 2 of 3, so I stopped at a garage and grabbed some Lucozade and Red Bull*, which meant that I didn't need to pick up my bottle I'd stashed for the start of lap 3. Unfortunately I didn't finish that one either, as the race was abandoned after a rider was
rear-ended and killed 
*Imagine the scene: there is an orderly queue for the checkout, when suddenly a sweaty, skinsuited Bunbury runs in, jumps the queue and throws a fiver on the counter, with a "Sorry, I'm in a race!"
