Ah, where to start...
With my first, I'd started out as a heavy caffeine drinker, I cut back, but I'll never forget the time my SIL (a labor and delivery nurse at Hopkins at that time) nearly had a heart attack when she saw me pick up a Coke. I later found out that for all her education, she believed every old wives tale on the planet and was the LAST person I'd consult about pregnancy issues. (she's since had two kids after tons of fertility treatments, so that has changed some). I DID discover on my own, that moderate caffeine intake didn't have any effect on my kids in utero, but when nursing
If you've never seen a two month old bounce off the walls, it ain't a pretty picture.
My most uncomfortable pregnancy was the one where I was under the most job stress. It was the only one I really had any morning sickness to speak of. I also had some bleeding around 8-9 weeks and some irregular test results, all of which were more scary then anything. So, like I said elsewhere, relax as much as possible, avoid those bad stress scenes as much as you can.
Also, stay off the scale. Your doctor will weigh you every visit, but don't worry about those numbers, even if the doctor gets on your case. If you are eating the right balance of foods, good stuff, not junk, you will likely see a little bit of a weight loss in the begining. Base your progress on how you feel, not the numbers. Don't "eat for two" eat the right foods and eat when you are hungry and quit when you aren't. Drink lots of water. It'll help flush out your system and keep you from retaining as much water.
If you find you are suffering from morning sickness, keep some crackers by your bed. The most common time for morning sickness is when your stomach is empty and it's made worse by the sudden change from laying down to sitting and/or sitting to standing. When I had it bad, it was usually when I got out of the car and started walking the two blocks to work. I knew where
all the trash cans were on that street.
I had that "what to expect..." book and I didn't like it. It's a nice reference. It tells you about the various tests you'll have and what they mean, but their advice on diet is stupid. No grilled meats, no tuna
They'd have you believe that if you don't follow their plan you are a bad mommy and are trying to hurt your baby. If you DO get that book, ignore the diet altogether and take every other piece of advice with a huge grain of salt.
Congrats.