I found out at 10wks gestation about my twins, too. They are 18 mths now. I had girls. My pg was pretty uneventful. and the delivery went off well too. Natural, no meds. A multiple pregnancy doesn't have to be scary or fraught with problems. If you have questions about the delvery aspect, be sure to some back to the forum!
The books mentioned are good. The EZ2Nurse pillow is a Godsend whether you nurse or not. Nursing twins is totally doable, but there can be some special considerations, so hooking up with your local LLL and trying to find other moms (IRL) that have nursed twins is very necessary. I was able to do it w/ no extra help with the nursing process, but I'd nursed 6 babies before that with no issues, and the twins were term with no health problems. I was very blessed all the way around. I suspect my case is somewhat rare. Line up the support ahead of time, so you are prepared for any outcome. Speaking of which, it is realistic to become familiar with all possible outcomes (regarding the pregnancy, birth, etc.) and what is involved with each one. Try not to get freaked out, but keep the perspective of "I am arming myself with knowledge so I will not be caught unaware and I can do my best to support the best possible outcome."
Anyway, I will cut to the chase or else I could type all day! One thing to keep in mind, at the END of your 2nd trimester your body will feel much like it would at the end of your THIRD tri, if you were carrying only one baby that is. But then there's that whole last trimester to endure! So, whatever you decide to do to prepare for babies, you will do yourself a favor to get it all done by then end of your 2nd trimester. Keep in mind, too, that the last month or so, your tummy may be so big that driving will be impossible because you will have to have the seat so far back to make room for your tummy that you won't be able to touch the pedals. I didn't realize this would be a problem, but it was. Aside from having help around after babies come (vital, for at least first 6 mths), it would be a good thing to have that help the last month or so as well.
One more piece of advice regarding nutrition. Besides eating plenty of fresh fruits and veggies and drinking at LEAST a gallon of water a day (not kidding) getting enough protein is your biggest concern. (if you would like some specifics on that, I will share if you ask). There are lots of different ideas about how much, I found 80-100 grams of protein a day was a good goal.
I have these books if you would like any of them. I will ship them to you for free. I only ask that you either pass them on to another mom for free when you are done, or send them back to me.
Having Twins and More by Elizabeth Noble
When You're Expecting Twins, etc. by Dr. Barbara Luke
Juggling Twins by Meghan Regan-Loomis (fun, funny read about preparing for life with twins. a bit mainstreamy, but found it very helpful)
Healthy Sleep, Happy Twins by Marc Weissbluth (full of sound advice; if your twins sleep well and regularly it will literally save your life!)
just PM me with your mailing address if you are interested