The best place to find gold is where it has already been found. Once you know where the gold mining regions are or were, you'll be in the best position to find gold again. But there is a saying, "Gold is where you find it." There are two types of places on the land to find gold: lode gold deposits and placer deposits. Lode gold is gold of a sizeable amount in rock in the ground, and a placer deposit is where bits and pieces of gold have migrated away from the lode due to erosion.
Pass a metal detector over the ground in an area you believe has lode gold or once had lode gold. If the nuggets are there and sizeable, the metal detector will pick up on it.
Look for a stream or river and examine the bends in the stream. Gold is very heavy and it gets stuck down deep in the bedrock, in crevices and in bends in the stream. If a river or stream suddenly widens, that's also a good place to dig down and look for gold.
Take samples in a stream or river with a gold pan. Load up the pan with dirt and rocks and swirl it around in a clockwise motion, allowing the larger pieces to wash away. Look down at the riffles (ribs) in the pan to see if there are specs of gold. If so, this may be a good place to set up to do more prospecting.
Obtain topographical maps from your local sporting goods store to get a feel for the terrain and to locate the streams and rivers to help you survey the land for gold. You can tell when you've found gold because it is shiny and gold in colour--not sparkly and prismatic like fool's gold. Also, it is much heavier than other sediment and rocks you will find in your gold pan, so it will sink to the bottom. And if you find a nugget, it is malleable--just press into it with your thumbnail or a knife to see if it indents. Then you know you have found gold.
Don't trespass on private property. Check with the Bureau of Land Management and the U.S. Forest Service in your state to determine where you can and cannot prospect.