Does your hospital have a website? They may have their NICU information there. Maybe ring up the unit and ask for a parent information leaflet. When you're admitted, try to arrange the tour straight away.
As for the way things work in the unit, I think it's one of those areas of care that are very similar in the US as it is here in the UK, so even posts you read from girls here in the UK should be very beneficial.
Every unit I've worked on/visited encourages parents to visit whenever they like, 24/7 (except if other babies are being discussed on ward rounds). Depending on how early your babies are born will depend on how the feeds and cares will be scheduled. Feeds can be from one to four hourly (or continuous) and, ultimately, demand. Cares for sicker babies tend to be done six hourly and then four hourly when they tolerate handling better. The nurse should always be happy to update you as to when babies' last feeds/cares were and when the next are due. Always feel free to ask if you can hold your babies - if the nurse feels they've had too much stimulation recently, they can show you how to do containment holding. A big part of the nurses' jobs is to facilitate family bonding and involve you in your babies' care.
And, yes, they'll promote breastfeeding - I can't imagine a unit in this day and age that wouldn't. I've found that most mums seem to think the neonatal nurses are a lot more helpful, encouraging and consistent with breastfeeding/expressing advice than the midwives on the postnatal wards are (no offence meant to midwives - they're ran off their feet dealing with loads of other things, whereas us NICU nurses can focus on baby-specific things), so feel free to ask their advice (you'll probably find that they're asking you how you wish to feed, how your expressing is going, etc before you get a word out about it!).