Wikipedia: Uputstva / Uređivanje članka
When you're on the page you want to edit, click the Edit button at the top of the page.
When you click Edit, the text of the page you are reading will appear in the edit box, where you can edit it at will.
After you have made all the changes, in the small field below the edit box - where it says Description of the change: - enter in brief the type of change you have made (eg capital letter, correction, etc.); this description will appear on the Recent Changes page, in the History of page changes, etc., and you can see the same before publishing in the Preview of the change description: field.
Preview before posting changes
When you're done making changes, be sure to click the Show Preview button, which is located below the edit box. This button will allow you to check if the modified article looks the way you envisioned, without your changes going into the Article Change History.
If you're not satisfied, continue editing, then click Show preview again.
TIPS BEFORE PUBLISHING CHANGES:
If you intend to make major changes or write longer text, multiple use of the Show Preview button will be necessary, so that the Page Change History is not unnecessarily loaded and burdened with a huge number of small changes. However, if you are only making a few small changes, check the This is a minor change option before posting.
If you want to keep track of what happens to the page you edit in the future, check the Monitor this page option. This will put the page you edited (and saved) on your Watchlist, which you can access via the link at the top of the page.
It is recommended that you periodically copy the text (ie code) of the page to your computer (in a text editing program) and save it there. This is useful because you can save texts (codes) of articles that you have edited on your computer, you can also write updates when you are not connected to the Internet, or prevent data loss if your web browser "freezes" by any chance, etc.
When you're sure you've made the changes you want, click the Post Change button. The page will then be saved to Wikipedia and ob�