Some clippers come with a nail guard, which prevent you from cutting too short and hitting the quick. That is what was suggested for me when I got Sugar last December.

Here is just one example (happens to be the one I bought)
http://www.petsmart.com/global/produ...l+clippers&N=2

Sugar is a small dog, just 12 pounds, so this is perfect. I have cut the wuick, both times I was at fault. Once I moved the guard aside to clip more; and the other time I clipped three times. Well, duh!

I usually cut her nails one every 4 weeks. I can tell when I hear her click - click - clicking on the kitchen floor that it is time to cut them. She does NOT like having them done. She lays on her back on the sofa and I clip a few. I spread it out over a few days to get through all of them, she looks so sad eyed when I'm doing it!