In the center of the Blog page - wide-field-button "publish material" - click on it by the mouse. The New Object Wizard opens. Enter its title. RIGHT side of the header field - You see three buttons: upload video, upload audio, upload image. Select one of these options and upload the appropriate file (you need files to be prepared).
In a large input window - write the text of the content (comment to the object corresponding to the object text). LEFT side of the main field and instructions - select the object settings, enter tags (ex.: house, dog, children), select the appropriate category / subcategory (you can enter any words, the system will probably offer a choice of category). Next, click the "publish material" button. Done!