Your profile says you're straight, so I assume its with a woman.
With the best will in the world, you're probably not going to be able to keep going as much as she is, so plan ahead:
Have lots of sex - get your stamina and staying power up
Invest in some delay tricks - cock rings/numbing sprays/virility tablets (maybe you should try some see which ones work for you)
I imagine at some more you'll need to resort to toys whilst one of you "recovers" - have you got enough batteries, have you got wipes/towels/tissues where you need them.
Ensure you have enough ideas to keep you busy. We like to start this kind of thing with a bondage session and edge play, which can use up a few hours, and is so very exciting. We also like to build in the odd photoshoot, which we both find very arousing. We also like sensual massage and blindfolded tickling type stuff. You can work in penetrative sex in between these, so that gives recovery time too. Generally we start hardcore and become romantic by the end, probably because we're getting knackered!
Make sure you keep hydrated - you aint going to come if you've got no fluid!
Stock up on lube
When we have something like this on the cards, I actually make a few notes about different ideas beforehand, because it's easy to get stuck doing the same thing all the time - you don't have to look at the notebook, but having it written down helps to remind me.