The idea of using a reference image to calibrate your monitor is a simple one. You simply adjust the brightness and colour of the monitor until it matches the print. Then in theory the screen should match subsequent prints.
Unfortunately this only works to a limited extent and can have pitfalls. Unless you are very skillful, and I'm not, you wont be able to match the contrast of each channel. You usually end up with a compromise. This can result in some what unpredictable results.
Generally you can get a reasonable match for brightness and white point. Contrast is a bit trickier, but can be done . ( I did this many years ago with Windows NT, an OS that had no colour management at all. The results were , shall we say variable. ).
If you really want to calibrate your monitor, and you want to ensure good print matching then you really need a device such as the Huey. This is really the only way to accurately calibrate and maintain that calibration. OK the Huey is £60-£70. but it does save one hell of a lot of grief