Great information taken from (http://dvcreators.net/discuss/archive/index.php/t-19414.html) about where your average and peak audio levels should be for your final product.  Also good for when you are recording your digital audio (this DOESN'T APPLY FOR ANALOGUE AUDIO!)  This is a must-read for new filmmakers and editors :

FOR MASTERING FINAL DIGITAL AUDIO :

-20dbFS (decibels full scale) is the standard scale for all digital audio output and it corresponds to 0db on the old analog view meter. The old system usually had 18db of head room above 0db before clip; therefore -20 corresponds to zero on the old analog format. This is 'average program level, not peak level.

Feature Film: (Full dynamic range) average level -20 with peaks up to zero (in theory) Well produced feature films are probably the best recorded audio tracks of all mediums and are meant to resemble reality. Try to simulate this practice with your final product.

Broadcast TV: -20 with peaks -5db measured over time. Here the lines become blurred as volume wars are common for the purposes of competitive advantage. Some broadcasters allow average levels of -14 to -12. All major broadcast corporations have their 'spec' sheet for deliverables which are available to the public. PBS has the strictest standards and their specifications are available in their 'red book'. If you do not meet the broadcasters 'online' delivery specifications for picture and sound your product will be rejected.
Note: Commercials which sound louder (typically 6db louder) are in fact the same level as regular programming. However, they use a smaller dynamic range resulting in 'perceived" louder sound output.

Music: -6db. Since the digital revolution mastering practices have evolved into a louder is better, no dynamic range volume war. The record industry started the practice of "competitive" loudness way back in the days of vinyl as they
thought that a louder record sounded better and got noticed resulting in higher unit sales

Internet: Typical of the web -- no standard, anything goes.  Around -10 dB to -6 dB is common.

Commercial video: Generally the same as Broadcast TV, except with heavy compression (an audio plug-in / effect) that emulates a "louder" sound without raising the values.