Depends on position (later the better obviously), table texture (loose passive the best and aggro the worst), who's acting after you and what their tendencies are, and then how many people are already in the pot. 4 limpers on and your on the button and then blinds aren't really aggressive=EASY limp/call.
You need enough people in the pot to get decent odds
with these cards because the typcial goal is to draw to a straight. As a pair (even 2 pair many times) they won't hold up. Calling cold and in early position, chuck em imo.