DoubleDesktop

If you're looking for an application that can create multiple active desktops on your screen, DoubleDesktop is one of the easiest to use out there.
The program has been designed to be aimed at beginners and more experienced users, so it's all very intuitive and featuring just a limited number of configuration options.
Once you launch it, DoubleDesktop places an icon in the System Tray that lets you switch from desktop 1 to desktop 2 and vice-versa.
It's usually enough to press the icon we were talking about, but additionally, the application also comes with hotkey support, which means you can easily jump from one desktop to another by pressing a user-defined keyboard shortcut.
The switch takes around one second and everything goes very smooth, regardless of the operating system you're using. Plus, it's recommended to have a look in the options screen as well because this is the only way to configure the aforementioned key combination.
In addition, since you're in “Options”, you may also change the icon titles and wallpapers for the two desktops, with very intuitive settings displayed for both of them.
Obviously, DoubleDesktop runs on low resources and doesn't hamper system performance in any way, while running all right on all Windows flavors, including Windows 7.
Overall, DoubleDesktop serves its purpose pretty easy and it does it with minimum configuration options, thus becoming a perfect tool for all beginners who wish to work on two different desktops at the same time. There's no help file included in the app, but since everything's so intuitive, you clearly don't need one.