I agree with the previous responses: tandem nursing was the only way we survived in the beginning.
A few other things that I found helpful:
I have my girls and my 3 yr old DS in a king bed with me, plus a crib side-carred to the bed. This gave me lots of room for all of us and all our paraphenilia: diapers, wipes, receiving/swaddle blankets, water bottle for me, extra sleepers/pjs for the girls (in the event of a poop explosion/spit up....), the ginormous nursing pillow (we used the my breast friend twins plus - a hand me down from a friend). I would nurse both at the same time and then change the diaper of whoever was finished first while the other was still nursing. I have a pretty good supply and just found it easier/simpler to assign each twin her own breast - this meant not having to switch sides/offer the other breast. My left breast seems to have more milk (we call it the power breast!) so for the first few months, I'd switch every week (whoever was on the power breast tended to gain faster. Now, 6 months in, they've seemed to regulate). I tried not changing diapers unless they had a poo, but found that in the beginning, their skin was too sensitive for that and I needed to change them after every feeding. I kept the room somewhat dark but had one night light that stayed on ALL. THE. TIME. This meant I didn't have to fiddle with light when they woke up.
I think one of the most important thing for us in those early days was really focussing on their latch and making sure that they were drinking well (vs. just nibbling at the breast). I found these videos http://www.breastfeedinginc.ca/content.php?pagename=videos , especially the ones of really young babies nursing, really helpful. Watch the first 4. I know watching some videos is probably the last thing you want to do right now, but trust me - they are super short and will completely change the way you approach each nursing session. Having a good latch and making sure they are drinking well means shorter more efficient feeds, which translates to more sleep for everyone.
Hope that helps.
HUGS and hang in there. It really does get easier.