Actually "Monitoring" can have more than one meaning.
"Monitor speakers" are used in the recording studio enviorment to listen to playback of what you are working on. Typical home stereo speakers tend to promote certain frequncies to make music sound "good" to a consumer's ears - low booming bass for example. However good monitor speakers will have a flatter frequency response, so you can accuately hear the full range of what you are working on.
"Monitors" also refer to speakers used in live music which are directed towards the performers, rather than the audiance. The idea being that you have to hear yourself and your fellow musicans clearly in order to play properly. Most mixing boards have a "Monitor out" section which is independant of the other outputs. This can be used in a studio enviorment also in order to feed the musicans an independant "mix" of what they are doing, or what they are overdubbing over. Headphones are often used in this case, and your "headphone" or "control room" mix can be yet another independant mix with its own levels.
I'm not an expert, so I can't give expert advise. But I will pass on some beginner lessions on reverb I have learned -
1) It is always best to record a voice or instrument "dry", that is without effects. Then add the effects later while you're mixing. But often vocalists like to hear their voice with some reverb on it - it makes them feel more comfortable. So if you have a mixer put some rerverb into the headphone or monitor mix that the vocalist hears while actually recording the voice "dry".
2) If you are using effects with a mixer, treat it like any other input. Namely you have to set effects levels. A signal going out of your mixer at 0db into your effects box should come back into your mixer at the same 0db, not lower or hotter.
3) When adding reverb to a mix, you need to keep the overall mix in mind. If you add reverb to a vocal so it sounds "lush", then add reverb to the drums so they sound "lush", then add reverb to the guitar so it sounds "lush", then play it all back together - you get "mush".
Hope this is useful. But ultimately if you are doing your own stuff, do what sounds good to YOU. You will find that as you continue to play with effects what sounds good to you will change over time. Good luck....