Here are some written instructions. Below is an excellent video tutorial. There are many more on line.
1.) Go to the “Meta” widget area on the right hand panel (side) of the blog; than click on “site admin” or “log in” hyperlink;
2.) Click on “add new”, located under the “post” tab;
3.) To insert picture, click on first icon next to upload or insert. Once you choose the picture from your desktop, you must click the insert into post button to make the picture a part of your post, then click save all changes. To insert video, there is another icon to the right of the insert picture icon.
4.) Follow the instructions to post picture or video.
5.) Click publish to create your new post; click update after you revise.