An audio engineer recently recommended any book written by Paul White:
http://www.amazon.com/Basic-Live-Sound-The-Series/dp/1860742718/ref=pd_sim_b_2
I was calling him to express my frustration that I could not control the monitor mix that I was hearing in the monitors. The issue turned out to be that the Mackie mixer we were using didn't have enough "auxilary sends" to be able to control the specific instrument/vocal levels that I needed at my monitor. "Pro" mixers have 2, 4, 6, 8, etc. "auxilary sends" so that each monitor can have it's own mix.
All of the other issues like power handling and main speakers can be worked out ala carte.
Common problem with bar bands. I have never provided more than one monitor mix. You want a separate monitor mix, you provide the PA
Hasn't worked though.... everybody is suddenly happy with the monitor mix

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