According to a thread in the yarvik forum (besides, the first hit on a Google search for yarvik tab411 root), you should be able to use the SuperOneClick tool. But while the name suggests "one click" should be pretty easy, it might be not the case.
However, you will need to:
- download SuperOneClick e.g. from here
- download and install the device drivers (for your device, possibly to be found on the yarvik's support pages) on your Windows machine
- activate USB Debugging on your device
- run the SuperOneClick application as administrator (oops) on Windows 7
- now the most difficult: click the "root" button :)
As I have no yarvik tablet, I could not check the above. It's just the result from a little Google search -- so forgive me in case it fails...