If you ask around or search the internet, you will find many differing opinions on what the proper setup is for a computer display. Some standards say 85 cd/m2 is the minimum and >100 is desirable. Some people say as bright as possible while others prefer a dimmer display. The truth is that you need to determine what works for you based on your environment and comfort. In general a higher contrast ratio (white luminance divided by black luminance) will allow you to see a greater range of tones. However, you would not want to introduce a loss of detail (clipping) at the white or black ends to achieve a higher contrast ratio.
In brightly lit environments, you will need a brighter monitor and lighter black point to see detail well. In a dark environment you will want a dimmer display. The most critical parts are that we capture accurate information about the monitor's response and that it is reproducing a full range of tones and not distorted. Then we can create a profile that tells applications how to display color accurately.
In most cases, you can set the display to your liking and use the "Profile Only" workflow to characterize the monitor in its present state. This option will not prompt you to adjust the display's settings, but will still measure its color response. It is also recommended that you use a desktop picture that includes a gradient of black to white, just to make sure the current settings aren't causing a loss of detail.