Maggarg, as someone who just got in before 2010:
*Hospitals- Are pretty easy, just assign a zone, put in some beds, make sure you have a well, and have a dude with diagnose enabled, rest is on wiki.
*Military - make a barrack, make a squad, set the squad to the training alert, set the barrack to be the training place for squads, follow the wiki for the rest.
*Main difference - material rewrite: silver hammers are much more useful than spoiler hammers, while spoiler swords are better than silver ones.
*Main difference 2 - All maps are potentially interesting. Don't worry about perfect embark for the beginning.
*New nasties - forgotten beast, night creatures, and other fun. The wiki has details, of course
*Zombies require pulping, so a squad of hammerdwarves pulping all their limbs into unrecognisable messes should work.
*more creatures.
*bees! (and beekeeping)
*animal training now works differently and requires a zone.
*mining skill no longer affects ore return.
*dwarves no longer haul things one at a time, they now they item weight and size into account. Stones are now slow to move without wheel barrows.
**Minecarts!
*main difference - The world now moves during play.
*This means your sieges come from actual world pops.
*this also means your kings, queens, liasons etc are from somewhere and will take time to get to you.
*burrows!(dwarves will only use burrows as job restrictions, not for anything else, except if the civilians are set to alert in that specific burrow)
*dwarven personalities, they affect things, and stuff.
*things are afraid, buggily so.
*trees! A lot of wood!
*for that matter, Clay!
You should be able to get going with what you've always known.