  Using the MIPS instrument on the Spitzer telescope, we have searched for
infrared excesses around a sample of 82 stars, mostly F, G, and K main-sequence
field stars, along with a small number of nearby M stars. These stars were
selected for their suitability for future observations by a variety of
planet-finding techniques. These observations provide information on the
asteroidal and cometary material orbiting these stars - data that can be
correlated with any planets that may eventually be found. We have found
significant excess 70um emission toward 12 stars. Combined with an earlier
study, we find an overall 70um excess detection rate of $13 \pm 3$% for mature
cool stars. Unlike the trend for planets to be found preferentially toward
stars with high metallicity, the incidence of debris disks is uncorrelated with
metallicity. By newly identifying 4 of these stars as having weak 24um excesses
(fluxes $\sim$10% above the stellar photosphere), we confirm a trend found in
earlier studies wherein a weak 24um excess is associated with a strong 70um
excess. Interestingly, we find no evidence for debris disks around 23 stars
cooler than K1, a result that is bolstered by a lack of excess around any of
the 38 K1-M6 stars in 2 companion surveys. One motivation for this study is the
fact that strong zodiacal emission can make it hard or impossible to detect
planets directly with future observatories like the {\it Terrestrial Planet
Finder (TPF)}. The observations reported here exclude a few stars with very
high levels of emission, $>$1,000 times the emission of our zodiacal cloud,
from direct planet searches. For the remainder of the sample, we set relatively
high limits on dust emission from asteroid belt counterparts.
