Speed of Skill use in combat?

[nightspaladin]

Can't find anything in the books about the speed of skill use. For a rogue to try to hide in combat, given the right situations that allow a stealth roll, does it take an action for them to do so?

 

[Surgoshan]

Tain't specifically mentioned. It would have to vary from check to check. A knowledge check about a monster might be a minor or free action dungeoneering or nature check. Running on the wall to get around a hobgoblin soldier so you can attack the shaman behind him would be a move action with an athletics check.