Otherwise, the hair closest to the skin will pack down, retain dirt and moisture and cause serious skin problems. If you brush the coat in small sections, reaching the skin is easier. Turn him over and repeat the process on the other side. Then he can stand or sit up so you can dry his ruff and bib. Long toenails damage feet and are uncomfortable to walk on.
Nails are easiest to cut after bathing when they're softest.
You may want to ask your vet or your dog's breeder to show you how the first time. No dog enjoys having his nails cut and you must be firm about it. Give treats and praise for being cooperative. With practice, he'll behave better and you'll become quicker and more efficient. Chows have the most compact, cat-like foot in all dogdom.