well there are 2 ways to approach this hand. If many people limped before you or 1 person raised a pretty small amount i would just call and go for the set. If there is 3 or 4 to act after you i would make a decent raise to maybe only get like A J or a decent hand in so you will have advantage preflop and only be heads up against 1 player.
i would limp in and hope to hit a set... although your chances are low it is nice when you do... don't forget online they give out pocket pairs in groups, i have gotten a set on 7's and someone else had a set of 9's or something similar many many times online
play them by position, if your on the button and everyone folds around to you, then raising with the 6's 7's or 8's etc isnt a bad idea, if you get them in first position or early to act, my best recommendation is to limp in then play accordingly