Snakes look a lot like sticks at first. In the beginning, you will find yourself stopping for every stick you see, but with practice you will learn that particular snake look, that is unique only to them. You will undoubtedly stop for a variety of odds and ends, including bicycle inner tubes, pieces of hose, fan belts and other goofy things. It is fun to write down in your log all the things you thought were snakes but weren't. Movement in the road.
Movement is the first obvious clue that there is an animal in the road.
But snakes and lizards are often just lying there absorbing heat, so there may be no movement whatsoever. Learn the visual difference between rattlesnakes and harmless snakes. Unless you are very knowledgeable about reptiles and are familiar with them, obviously do not get out of the car to go look at a rattlesnake. Although they are actually quite shy and generally strike only when provoked or startled, a novice should enjoy looking at them only from the car. You can drive right up to the snake and everyone can enjoy looking at it safely out the car window with the flashlight.