Weel, yes and no. You're going to use a CD that you're very familiar with. Something that you listen to often and on different systems. Listen to that CD through your monitors for a few hours, or days. Then, when you go to mix down your own music, you will have a better idea of what it should sound like. The idea here is that all speakers (monitors, car stereo, home stereo) sound different. You need to train your ears to recognize the particular sound of your monitors. Keep in mind though, if your monitors lack low end oomph, or high end sizzle, you will be overcompensating for it in your mix. That's why you have to be very familiar with how they sound. Something else that should be mentioned here... Don't forget that setting levels is only the first step in the process. There's effects and EQ in most mixes to make sure all the instruments and vocals can be heard. Then, if you were actually producing a commercial CD, you would sent it off to a Mastering Engineer to make some final adjustments to the whole thing before it gets released.
This is not an overnight learning process, but don't give up. Most people spend years to learn how to mix properly. Keep trying and by all means, experiment. You might just stumble across something great.
