This tip may come a bit too late however it's the single most valuable piece of information I received. You have to start cutting nails from day one. Ideally, your dog is a puppy and you can cut nails atleast once a week, twice a week is preferred. Now if you are cutting them this often, you hardly take any length off. The idea is you get them used to the tools you use. You can also use treats. My in-laws rescued 8 year old Irish Setters. They were in rough shape as they were coming from mills.

We found a treat that they loved. Then, one of us would hold the dog and have a treat in the other hand while the other person would focus solely on cutting the nails. Eventually they learned that when we got the nail clippers they would get a treat and they loved getting their nails done.