Here is a short shopping list to get you started
1 Car with 4 doors/4 door pick/up or 1 mini Van with 4 doors
1 diaper bag
2 Cribs
2 Car seats
2 Swings
2 Bouncy Chairs
2 High Chairs
1 Playpen Large (for 2)
about 20 sleepers
10 bottles
about 100 shares in either Huggies or Pampers
1 Cow (for the milk you will go through)
If the kids will be on formula buy the powered stuff it is cheaper than the pre mixed.
In all seriousness Twins are a blessing and if I didn't say it earlier Congrats