Do you mean direct or link to an off-site like Photobucket? If direct the size has a limit, but the process is as follows.
Select FULL Editor,then at the bottom of the screen you will see an option UPLOAD ATTACHMENT. Click this one time, Filename option CHOSE FILE.
Selecting this will open your file index and you will have to select which files have the pictures you want to post then the specific picture.Once you select the picture the original screen will appear.
At this point if you want to load more than one photo then repeat the process.
After selecting the picture click ADD THE FILE and this will prepare the picture for insertion into your post. At this point you need to make sure the cursor is below your text or the address / picture will split your text.
Now you should see a posted attachment box below your text. you have the option to add a comment to your picture. Again the cursor should be below your text. Now select place inline
the attachment and comment will appear in your post, now just hit preview to check your post and then submit or select submit.
Now if their is a hesitation and then a blank post appears with your text gone the picture is to large and has to be resized. Back arrow at the top of your screen will take you back to the screen prior to when you hit submit. Give it a try,also you can use the search option on the forum to get information about picture size.
cheers Saxondog