There are some files on the internet you can download, Bluesky Media is one site, they are monitor calibration files. They are recorded at
-20db from 500 -2500 Hz. You will need a Radioshack SPL meter ($39) and you use these files to set your monitors. Recommendations are anywhere from 73 -85 db to correlate with the Fletcher Munson curve. This is the range in which the frequency scale is somewhat flat to the human ear.
Once you are done you have your maximum volume setting for your room and monitors. Most sane people build a mix at lower volumes and then run it up to 85 db for a few minutes at the end, just to make final adjustments to the overall balance and.... to save their ears.
You can get even more focused and get hold of a calibration CD which has test tones from 30Hz to 20KHz. You play these files and chart the volume level your SPL reads for each tone. This will help you find room nodes and nulls.
If you have a small room your chart will quickly tell you that you have excessive bass volume, a severe drop off in the 100-125 Hz range and lower overall mid and upper frequency response. This is why small rooms need bass traps, to soak up the low end and balance with the upper and mid range frequencies.
The idea is to balance your overall room at the mixing position. This will improve your ability to make the proper EQ adjustments and lower the number of trips to the car to check your translation.