With man voices, i tend to cut it around 80Hz. I cut this band around 450-500, with really great results. THen boost the mid range at around 3-4k. Both for 3-4dB, or whatever is necessary. And then i boost the high's with the hgh shelf at around 8-9k

The "cut narrow, boost wide" guideline applies to vocals perhaps more than any instrument. Our ears have evolved remarkable sensitivity to the sound of human speech. (Consider how easily we pick up a single conversation in a crowded noisy room.) So we're immediately, instinctively aware when a voice has been processed unnaturally.

High-pass: Most vocals - though of course not all - benefit from a low cut filter. The average fundamental frequency in an adult male voice is 125Hz, and often you can roll off up to 180Hz without affecting the sound. (If your mic or preamp has a low-cut filter, consider engaging it when recording vocals, as most subsonic audio in a vocal track consists of mic-stand noise, breath rumble, popping, and other undesirable sounds.)

• To reduce a nasal sound, try dipping a few dB around 1kHz, and moving the center frequency slightly up or down to find the most effective point.
• To treat popping P's and T's, cut everything below 80 Hz.
• For a little extra clarity and presence, try gently boosting the "vocal presence range" between 4kHz and 6kHz.

I kind of like a little high-shelf from 5khz and up, by a couple db as well, and a db of 3khz (about one octave width, on the lead singer only), in addition to what Des mentions. Not as a general rule, mind you, just something to try.