As a starting point, I sometimes will look at a frequency analyzer to see if there are any overly weak or strong areas in the spectrum.
Dont mean to hijack the thread but this question may also be relavant to the OP.
I have Spek installed but have no idea how to read the output.
What would the output attached show?
Spectrals can be very useful on a number of levels but in terms of eq would not necessarily be my go-to view unless I'm looking for a noise that doesn't belong.
The spectral provides a view of the relative intensity of the sound across the range of frequencies. It's often a red at the bottom lowest and moves progressively to a lighter color and black where there's nothing.
It's real good for seeing how high the signal reaches. Cheaper mics or doctored recordings usually stop at 20K or below but the Schoeps will show information all the way up as high as the scale goes (though for mastering engineers typically set an upper limit above audible range like 22K or so and remove anything above that).
It also shows quality of the signal (when you zoom in a very smooth. blurred continuity is what you want to see, not the brick squares you'd see from MP3 compression).
The one you posted looks fairly normal and does not really show anything I'd necessarily be concerned by.
Sometimes if there is some sort of fault (buzz or hum) you may see a solid band straight across at a certain frequency or a red band somewhere way up where you wouldn't normally see it or alternatively there might be gaps where there are weak areas or something missing. It can show you where to look to notch something out with a filter (though a frequency plot will often show that if you zoom enough on something obnoxious).
I think the frequency plot (like the Ozone pic below yours) is a lot more useful for eqing a fairly normal source.