I will be installing a bathroom sink over granite tiles and need to know if there are measurement standards used to center a sink from the backspash to the front edge. Also, my sink is a drop in, is there anything I need to do to keep the sink from moving around once installed. The guy at the plumbing store told me that the caulk and plumbing pipes will be enough to keep it in place. Advice is appreciated. Thanks.

I'm not going to say the pipes will keep it in place, because if that is all that held it there it would move around, drop in sinks are held in by %100 silicone. Run a bead underneath the lip of the sink before you set it, and here's a tip, do all your plumming fixtures before you set the sink this way your not under the sink as much, once you set the sink you should have to do more than hook up the supply lines and tighten the drain trap. You can do a dry fit before you use the silicone