Go to this link and download a free version of screen hunter and install it.
http://www.wisdom-soft.com/downloads/downloadfiles.htm You can set it up so that a hot key starts the process of takeing a screen shot. I set mine to the PrtScn (Print Screen) button. You can choose which folder to save you screen shots too. I made a folder named screen shots on my desktop to save to. There are other options you can set as well. I set the type image to Jpeg. Once you have screen shots you want to post, go to the reply page or start a new topic tab. To the lower left of the reply box you will see additional options. Click on it and use the browse button beside the attach: box to browse to your picture or most other type files. The allowed type file extensions are listed below the Attach: box. You can post up to 4 attachments per reply so if you want to post more than one beside the browse button you will see more attachments. You can't have two files named the same thing in a directory and the forum is no exception to that so I use the options in screen hunter to name my screen shots a unique name by using the date and time in the file name.
Brett