I've done this and yeah, I always felt awful. Now I take the girls to the vet to do it.
Have the following items just in case. A shallow bowl of flour, white, unbleached, heck, even wheat flour is fine. Baking soda is okay too. Also a cotton ball and a bit of self sticky athletic wrap. It shouldn't bleed for long, but if oyu have carpets he'll walk on, you want to make sure. Dip the nail into the flour, then put the cotton ball over it, and secure it not too tightly with the athletic tape. Leave it on for a good half hour.
Weekly trims, just the tip of the nail, will cause the quick to retreat back further in the nail. Some dogs even like their nails filed with a Dremil brand electric hand-held drill/buffer thing. But some dogs hate the noise and vibrations.
Also running your pups on a hard surface like concrete helps wear them down naturally. Don't forget you'll still have to clip the dewclaws (on the sides) if he still has them!
AND, you should (EVERYONE with pets should) have a emergency first aid kit with the above items in it along with others like Q-tips, clean rags, a pair of round tipped scissors (Nurses' Scissors are perfect) a plastic bottle of Hydrogen Peroxide, (to clean wounds, it doesn't sting, but it does foam up!), a towel or blanket large enough to hold the pet should you need to trandsport him someplace, a spare leash, preferably one with a simple slip noose type collar, a bottle of water, a collapsible bowl, rectal thermometer, pair of grasping tweezers, small pair of wire cutters (for fish hooks, fence peices and "S" hooks on collars), a pen knife, Neosporine for small cuts, Rescue Remedy to help ease a stressful situation, as well as a little flask of something for you. ALso have inside this kit, your dogs name and the name of his usual vet. If your pup also has seen a lucom you like, put his name down too. Keep a copy of ALL of your dogs vaccinations in there, in an emergency situation, you will need to have them.