I can't believe, me, the computer illiterate is gonna attempt to explain this but here goes.
First its manage attachments then browse. When you select a file and then a photo, right click on the photo, options will come up and left click on edit. Then select re-size with a left click. It should display some pre-set dimensions or choose your own. I have been going with my own, 600 by 400 pixels. Make sure to hit O/K before exiting and upon doing that it will then ask to save changes, yes.
Then its open and upload and you got it.
That is how this gadget works
If anyone is helped by this it will be a true testament to the power of POG