What is a fossil?

Fossils are the remains of long-dead plants and animals that never rotten and have after many years, become part of the Earth’s crust. Fossils may be the rest of the organism by itself, impressions leaved by them in the sediment or traces made by them in life.
As examples of fossils we have (fill this out with images or pictures!):

For fossilization process to occur, the organism (or part of it) has to taken by the water to be rapidly buried in the sediment, then chemical alterations occur for many years where minerals are added or removed helping to the preservation. The fossilizacion process is as fallows (See the following video and fill the next part out)

How do paleontologist find fossils?