Find a Notebook shared from the IPython Notebook Gallery and Download it via http://nbviewer.org. Then import it into your running Notebook server using the Dashboard.
Recall, the Notebook can contain cells of the following types:
Create a new Notebook that has at least one of each cell type. Practice the following cell operations:
Go back to that last Notebook and repeat some of those cell operations using keyboard shortcuts:
If you still have time, study the notebook titled "Markdown Cells" and solve the small exercises included therein.