Haven't had a chance to look at the circuit, but this should help you get started (from Wampler's book)
More from wampler:
"*Free online calculator at
http://www.muzique.com/schem/filter.htmKeep in mind that R1 and C1 affect the same frequencies in high AND low pass filters. The
difference is that they affect them differently. For example, if your high pass filter has the values
10k for R1 and .047uF for C1 then most of the frequencies BELOW 338hz are limited, or not
passed through (actually, not ALL frequencies are limited, but 6db per octave pertaining to the
cutoff frequency). In a low pass filter with the same values the frequencies ABOVE 338hz are
limited."