A simple free program that I often use is ontop. On top makes a window always stay on top of other windows. This is useful if you want to copy things from one window to another or if you want to look at two documents simultaneously.
Ontop works very easily. You run it either manually or place a shortcut to it in your start menu startup folder and it will run on windows startup. When running ontop displays a small icon in the system tray. Using it is very simple. Just right click on a window title bar and you’ll see the new option "Always on top". Click on that and your window will never be buried. Click it again to make it function like all other windows.
Author’s site (strangely empty)