Others have detailed the procedure for countless other newbies, myself included, so here's my turn to return the favor...
I'm not sure there is an "easiest" way to do it, but the individual steps are easy, there's just a lot of them!
Step 1:
Navigate to your photo album. I've found the quickest way to do this is to log-in, then scroll down on your right to the list of current users, click on your own username to bring up your profile, then click on your photo album and navigate to the photo you want.
Step 2:
From your photo album, click on the image you want to insert.
Step 3:
While viewing the image you want to insert, click on it again, which brings up the full size version.
Step 4:
With the full size image now displayed, right click on the image (assuming Windows OS), and select "Copy Image Location"
Step 5:
Now in your message body, where you want to insert your image, click on the "Img*" button above the text editor. This inserts an img html tag into your message.
Step 6:
Now paste the address of the image to the right of the img tag (you can use Ctrl-V to paste, or you could also right-click then hit "paste"). Verify that the image address ends in an ".jpg", not a webpage such as ".html".
Step 7:
Click the "Img" button again to insert the /img tag after your image address.
Step 8:
Click the Preview button at bottom of screen to make sure it all looks good.
Step 9:
If all looks good, hit the Submit button!
