I am struggling a bit with this. It is our first campaign so it is new for all, including myself. So far I tried to let them experience as much as I could beyond the basic rules. This makes it more adventurous but on the other hand deprives them of some tactical options they might otherwise have.
Do you explain all mechanics, enemy skills, statblocks etc. before the party encounters them or do you let them experience it and let them figure it out as they go?
For example:
Do you explain hideous toughness when fighting a troll or let them be surprised and startled when he regains endurance?
Do you say that an enemy has 60 endurance and now has only 3 remaining, or that he is as hardy as a family of dwarves and near his death now?
Curious about your insights and ideas.