Best way to post images from T11 is to hit 'prnt scrn' button on your computer, then go into MS Paint and hit 'paste' and you will see the screen shot, You can edit the screenshot by MS Paint and remove things like the web browser and cut the image to show the important section, also you can add transparent text which some users use to display team quality on the image in cup draws or the league table for example. once you are happy with your image, save the file and upload it on 'tinypic.com' and they will give you a IMG code that you need to copy and paste into your message your typing in on your forum posts.
I don't know what program to use to replace 'MS Paint' for Mac users since I use a windows PC.