In general, there are two ways of thinking in my opinion when you first open the action with a small pair. The first is to open limp, the action in which the first player hits the flop calls the blinds instead of raising, hoping to encourage other players to limp behind marginal holdings. This keeps your investment preflop to a minimum and encourages multi-way action, so in the event you do get a set on the flop, action is more likely. The second strategy is to open with a raise from middle or late position and simply fold early. By raising instead of limping, you can keep your range "no limit" (as you would play your best starting hands in the same way) and seize the initiative. When you get called, the pot will be bigger than if you had limped, which makes building a big pot easier postflop when you have a set on the flop. And in situations where everyone folds, winning the blinds is never a bad thing! Having said that, if your opponents are inexperienced, play too many hands, and/or are not paying attention, a limp strategy may yield the best results.