I think the fact you are aware they may be issues that come up and are trying to do prep now will make things go more smoothly. My first 2 are 22 months apart, and there's 35 months between #2 and #3. Here are some things that worked for us:
**We did read a handful of the "big sister" type books - you may be doing this already anyway - sometimes it was a good way to relate what my child was feeling to the character in the book and the fact that it was OK.
**Do whatever changes you can ahead of time. For example, try to move out of the crib, to a new room, etc. a few months before the new baby if possible so your older child doesn't associate the changes with the new baby. And always stress that she's such a big girl now that she gets to go to the big girl bed (or whatever) and be really excited about it. Don't even mention it's because of the baby.
**Likewise, if your daughter is used to being carried a lot, try to break the habit before the new baby comes. I was forced to do this early in my pregnancy with my second since I was told no lifting, but it was great that my oldest was already used to climbing into her carseat, high chair, etc. and not expected to be carried everywhere.
**Prepare your daughter for you being gone overnight, etc. In my case I had c-sections and was gone for a few days. Make sure your DD knows you are OK and who will be taking care of her (do a test run with whoever will be staying with her if it's new to her). I also made sure to call at bedtime (and maybe another time during the day) and daddy usually went home for the bedtime routine. Things will be different than usual, but if you can keep her schedule and routines as consistent as possible it will be reassuring to her. I typed out our daily schedule so the grandparents could stay close to normal.
**I recommend letting your DD come visit in the hospital unless you'll be there a very short time. And when she comes, be sure to have the baby in the bassinet or someone else's arms so you're free to give big hugs and cuddles.
**I also bought and wrapped up little gifts for my older kids for each day I would be gone. Small craft kits (like the $1 ones) were fun and gave the caretakers something to do with the kids. Also picture frames with pics of the child or mommy and child. Most things were just $1 or so, but it still helped them feel mommy was thinking of them.
**When you come home, invite the older child to join you for things, but don't force it. My oldest wouldn't get in a "family" homecoming pic when the second came home, and I just lat it go. Within a couple days she loved being in pics with the baby.
**Before I sat down to feed the baby, I would always make sure the older one(s) had a snack and drink too. Sometimes we would read while I fed the baby or they would play something else, but the snack helped a lot.
**The baby will obviously require a lot more care in the beginning, but try to make sure the older child doesn't always feel like she comes 2nd. Sometimes even if the baby didn't really need me, I would say "I'll be right there (baby), your sister needs something right now." Kind of hokey, but I think made the older one(s) feel sometimes the baby had to wait for them.
**Try to have a little "big girl" time most days if you can. It's hard, but I would try to take even 15-20 minutes to read, to a craft, or just snuggle with the older one(s) while the baby was sleeping. A little time makes a big difference to them.
**Also, maybe start getting your DD used to a different bedtime routine if needed. When my oldest was little, DH and I used to both put her to bed. When I was pregnant with #2, we started taking turns so he did one night and I did the next. That way after the baby came, older DD was used to just one of putting her to bed if the baby needed one of us.
Sorry it's so long, but hopefully there's something helpful there for you.