When you are on the screen you want to post, click PRT SCR (Print Screen) which is usually found above the insert button, this is on a QWERTY keyboard. Next you need to go into paint or Photoshop or whatever, and paste the picture into the document. Save it s a PNG or a JPG. Next go to
ImageShack® - Hosting and by the upload tool, browse for the file you want to upload. Once uploaded copy the link it gives you for Forums 1 or Forums 2 and paste it into a post, and it should come up. If you have any trouble, we are here!
EDIT:An easier way is, press alt + f9 the just go to imageshack.us and upload your image from, my documents/Sports interactive/Football manager 2008/ Screenshots, much quicker way of doing it.