Wet the hand that you're going to handle the fish with.
Remember, the slime on the fish is what stands between it and disease, so leave it on the fish!
Slide your (wet) hand gently from the head of the fish, (thumb near the belly, pinky on the "forehead"), down the fish, holding the dorsal fin down, as you go.
Hold firmly, but gently at the midsection of the fish.
Use small pliers to remove hooks with barbs, using a slight twisting motion.
And, um, don't try this on a large fish!
Take care not to injure the fish and you'll get the hang of it in no time!
PS. The back of the gill plate (the bony portion that opens and closes)can slice you open too, if you're not careful!