In a browser go to your edublog, and login using your normal username and password.
Select the + and then Post to add a new post.
Give your post a (shortish) descriptive title,
Add the body text,
Select the category(ies) your post fits in best (these allow visitors to look at a collection of posts by a category, eg events),
Add any keywords as tags (these make it easier for search engines to find)
Once you are happy select “Publish”
That’s it.