Is it possible to see progress for individual achievements in Steam?
For example in Skyrim, there's the achievement "Delver" (clear 50 dungeons), and we're wondering what number we're at.
Steam doesn't show your progress for the achievements in Skyrim.
However, you can track your progress via the ingame general stats section. Those numbers are synched with steam to unlock your achievements.
It depends on the game.
Most of the time, yes.
I know there are a few achievements for Team Fortress 2 that don't display correctly on your Steam profile, but do through the in-game achievement interface.
Achievements that require a lot of doing something usually have some sorts of milestones that pop up.