A fossil is the remains of an animal or plant that was once alive but is now dead. When the remains of an animal or plant become a fossil it is called fossilization.
How are fossils formed? 
To show you how dinosaurs became fossils, here is a normal fossilization:
- The dinosaur dies and is washed away in a flood. The body is buried in sediment (mud or sand) and eventually the body is covered.
- The soft parts of the body are destroyed leaving only bones. Minerals from the sediment soak into the bones. Very slowly, minerals start to replace the bone. This turns the bones into stone.
- Over millions of years, parts of the rock on the surface wear away. Eventually, the fossil skeleton comes to the surface and is discovered.
Where are fossils found? 
Fossils have been found all over the world. Places where many fossils are found are called sometimes called 'fossil hotspots'. Famous ones include:
- Ghost Ranch, La Brea Tar Pits and Morrison Formation in the U.S.A.
- Burgess Shale in Canada.
- Messel Shale in Germany.
- The Gobi Desert in Asia.
- The Isle of Wight and London Clay in the U.K.
- The Jurassic Coast in Dorset, U.K.
- Dinosaur Cove in Australia.
What are trace fossils 
Trace fossils are fossils that are not of the actual body, trace fossils include:
- Fossilized footprints.
- Fossilized eggshells.
- Fossilized nests.
- Fossilized droppings, these are called coprolites.
- Fossilized skeletons of animals.
- Fossilized plants.
What should I do if I find a fossil? 
It is unlikely that you will find a fossil but it could happen! If you think you've found a fossil then take it to a local museum or college and they can examine and tell you what it is. If you're really, really lucky it might be a new species of dinosaur. They could name it after you! However you should never go around digging up the ground with spades and shovels. Leave it to the experts! When you are an adult you can do this without experts but make sure you check with the police to make sure digging up dinosaur bone without experts is legal in your state/country