If you have multiple pictures to add, this will not suit your needs. This is only to add a single picture. There are other ways of doing it, and some are better, but this one is straight forward and easy, so I'm going with this method.
Step 1: Enter your status update
First step is to enter your status update, and then click on the Picture button next to the word Attach.
Step 2: Browse for the file
When you click on Upload a photo, you'll see a new screen that will give you a Browse button. Click the Browse button to start browsing your computer for the picture.
Step 3: Find your picture
Note that this step is specific for Windows, but other operating systems will be similar.