Its very simple!
Just click on the page where you want to insert an image.
Click on the Insert menu on the menu bar on top.
Select 'Picture' from the drop-down list.
Select the type of image you want to insert like clipart, from file, etc.
From the dialog box that appears, select the appropriate image and then click insert.
Thats it! The image will be displayed where you had put your curser on the page.