Coming from 3.5 to Pathfinder has been interesting in that while it was an update to 3.X, some of the mechanics have changed. An example of this is a PF Rogue's Sneak Attack.
In 3.5 a Rogue could not sneak attack an undead creature. It made for some boring battles for the party Rogue in an undead-heavy campaign or session. Pathfinder seemingly has changed this under the Sneak Attack rules (page 68 PFCR) in that, "The rogue’s attack deals extra damage anytime her target would be denied a Dexterity bonus to AC (whether the target actually has a Dexterity bonus or not), or when the rogue flanks her target." There is no mention in the Pathfinder rules if Rogues are still unable to Sneak Attack an undead opponent.
So, can a Pathfinder Rogue add their Sneak Attack damage into their attack on an undead opponent?