Summarize:

While most frogs will be found near water, you’ll want to know what frogs are in your area if there are any dangerous frogs (poison dart frogs, etc.) in the area, and what their habitat is. Research can also help you find useful tips for finding specific frogs by helping you identify their calls or markings. Many states have websites about their local species. Most species are nocturnal, so you may not find any in the day. Be careful of other dangerous species during that time. Snakes are often found in similar areas as frogs and newts, especially as many snakes, including the very venomous cottonmouth, will eat some amphibians as part of their diet. Never put your hands where you can't see them.  It's a good idea to use a flashlight. Using a red flashlight, or covering the flashlight with red plastic wrap or tissue paper will cause minimal disturbance for nocturnal animals.  You can also use night vision goggles. Though night birding is often the most common use for specialty night-vision goggles, they can be useful in seeing frogs and newts as well. Most frogs and newts live near water. When looking for newts it’s also useful to look under rocks and logs. Any place where there are ponds or lakes, including forests and meadows may attract different species of frogs. Many species hibernate in the winter. The best time to find them is in the spring or summer. If you live in a colder climate with a late spring or an early fall, summer’s the best bet. A canoe is quieter than a motor boat and will allow you to approach the frogs quietly. Ponds, lakes and river deltas are all great places to look for frogs and newts. You will often find frogs and newts near the bank or among plant life along the shore. If you shine a light on frogs while canoeing, they will often sit completely still.
Do your research. Look for frogs or newts at night. Look for frogs or newts near ponds or lakes. Look for frogs or newts in the spring and summer. Go canoeing at night or in the evening.