Please note this video covers the editor Potlatch 2. There is now an even easier editor for beginners: iD. This has a built-in tutorial. Head over to the osm.org web site and click Edit to begin.
This short video demonstrates how to add points of interest (POIs), such as shops and cafes, to OpenStreetMap (using the in-browser editor, Potlatch 2).
Please note: this video states that the Save button is in the top right-hand corner. However, it has now moved to the left!