What i do if i am taking a snapshot in game is ctrl + prntscr, then I open paint and ctrl + v.
to paste it onto paint. Once that is done , File, SaveAs, lable the file name, drop the SaveAs Type scroll down at bottom to PNG or *PNG then save it… once its saved to probably my pictures or whatever destination you pick, you can then go to imgur as izzy stated and upload the file. Now that its uploaded you can click the type of description to the right you want. If you were to post it in a forum like this click BBcode and then ctrl+v to paste it in and then you may preview it before sending