The fossil record, a kind of catalog of existing fossils, gives us a picture of evolution by showing the incremental changes in species throughout time, and helps students understand the immensity of geological time.
Students learn to find patterns in the fossil record, and use these observations to create theories or hypotheses about where fossils came from, and what we can learn from them. This can start them on the road to using the scientific method to test theories and can possibly create an interest that will lead to a career in science.
Students are often interested in fossils, and this interest can help nudge reluctant readers into extracurricular reading on the subject, as well as encourage them to participate in classroom reading assignments more fully because they are about fossils. Similarly, the interest may be used to incite enthusiasm for story problems in math that are built around fossils and related subjects.
The study of fossils helps fulfill the National Science Standards study of Earth science, which includes an understanding of Earth's history and changes in Earth through time, as well as evolution. It allows for content with which to practice the scientific method of inquiry, also required in the National Science Standards.
Even very young children can begin to explore fossils, especially enjoying dinosaur fossils. They can also learn more about how fossils are made be creating plaster or clay fossils.