The Fourfold way is the basic set of steps used for all edits.
Step 1. Click the edit tab to start making your edits.
Step 2. Enter a note in the edit Summary so others know what you have done. A summary might be as simple as "fix typos", "add links" or "add photo". Not leaving a summary is very bad form.
Step 3. Show preview to check your changes. If it isn't right, go back and do more editing. Every time you save, you create a version of the page that will be saved forever. Unnecessary saves create unnecessary load when backing up the database. Be kind to the server and preview before saving.
Step 4. When you have checked everything, click Save page.