Dapper,
Download all types of freeware at cnet.
I like "snip-it" for screen captures ... use it about everyday at work. Easy to learn/use and you can get just a piece of the screen if that is all you are interested in.
Here below is the link pointing you in that direction. You can just search along the lines of "free download screen capture snip-it software."
www.cnet.com
Always notice cnet's ratings on their freebies software. Too, ensure it is compatible with your particular platform. It should indicate the operating system. Examples: windows, mac, etc.
If cnet gave it a poor rating, you don't want it. Download the free versions.
Lots of goodies there. Have fun!