Shorter than most humans, stocky, sturdy. The ones that live above ground are called surfacers or surface dwarves--those are mostly descendants of some of the merchant caste, or of various kinds of exiles from other castes, or from castless dwarves who decided to look for a better future. Above ground--and below, too--you've got various groups or families of the Carta, which is into smuggling lyrium and other shady activities.
Underground, the main city is Orzammar, which is ruled by a king. Castes include noble, warrior, artisan, smith, merchant, and servant castes. The casteless live in a separate part of the city. Most of what I know about Orzammar I know from reading or talking to others; House Cadash was once part of the warrior caste, but it was exiled long ago, and now we're mostly Carta.
Lyrium is...complicated. It's a mineral, blue and glowy, and only dwarves can handle the raw form safely. It has to be processed before mages or Templars can use it.
I used daggers, mainly. And for a time this glowing...Anchor mark on my lady hand. My companions included archers and swordsmen mages. Had some troops, too, and some spies and diplomats and other allies.