Congratulations! My twins are almost 2.5, and we have another baby coming in about 3 months. My first piece of advice is to find a local twins club (visit www.nomotc.org to find one). I thought it sounded dorky at first, but I cannot imagine being pregnant with and raising my twins without the support I've received from the other women who have been there, too!
The first months will be a challenge, no doubt about it. Keep them on the same schedule. When one wakes to feed, ALWAYS wake the other. Even, if you feel like they just ate, always feed them together. This kept my sanity and allowed me to sleep in the beginning. Otherwise, you feed one baby, put it down, then the other eats, and by the time this feeding is done, you have about 20 minutes before it's time to start all over again. If you're breastfeeding (which I did), this cycle takes even more time.
I had my mom for a week, but after that I was on my own. My husband went back to work when they were 11 days old. He worked 12 hour shifts twice a week, so for the first month I had my cousin come over for a few hours on one of those days. There were days I cried - call someone as soon as you feel the stress coming on!
When the babies were four weeks old I ventured out for the first time by myself. After that, I went out EVERY day. I needed to for my own sanity.
Even though they are individuals, in terms of their care, treat them like one baby. Change diapers at the same time, feed at the same time, bathe on the same nights, try to get them to sleep at the same time. These things will help them to develop the same schedule, which my twins have always been on.
Most importantly, know that you CAN do this! It is an amazing journey and I would do it again in a heartbeat!