Voice over compression suggestions

I'd say compression is exactly the opposite of what's required, as this inherently raises low level sounds and reduces higher level sounds.

Look instead at a decent expander

Thanks Jeff, that's exactly the type of advice I was looking for (and a bit more squashing than I initially was going to use).  Expansion was definitely not what I was needing (though some do say I should be more dynamic ).  Just try listening to Classical music while driving and it will prove your statement about losing half of the message! 
 
I will be recording in a quiet environment so I'm not worried about raising the noise level by compressing.
 
Can you explain more about what you mean when you say "even out all the phrases?"
 
Thanks again!

I am a fan of opening individual tracks that have been recorded in an editing program such as Adobe Audition. I believe many things can be improved there before a mix occurs. With a voice over when you look at the track you will see the average level of each word/sentence/phrases and I am referring to the main part of the sound not the peaks so much.

Some words or phrases may be a few db low and some others a little high. I like to pull up any lower level phrases and bring down any over high level phrases to match the overall level of the bulk of the signal.

The compressor which follows later is then working on a very even track and therefore does not have to over react to a high level peak etc.. It will sound a little more natural and transparent. But this is not an absolute essential either. If the VO person is good they will read evenly anyway.

Kalle's sugestion is also good except I tend to set the HP filter right on the microphone before the signal even goes into the DAW. Be careful rolling off low end especially if the person has a lowish deep voice as you can thin it out too much too and it won't be as effective.