  We present a full sky 100 micron map that is a reprocessed composite of the
COBE/DIRBE and IRAS/ISSA maps, with the zodiacal foreground and confirmed point
sources removed. Before using the ISSA maps, we remove the remaining artifacts
from the IRAS scan pattern. Using the DIRBE 100 micron and 240 micron data, we
have constructed a map of the dust temperature, so that the 100 micron map can
be converted to a map proportional to dust column density. The result of these
manipulations is a map with DIRBE-quality calibration and IRAS resolution.
  To generate the full sky dust maps, we must first remove zodiacal light
contamination as well as a possible cosmic infrared background (CIB). This is
done via a regression analysis of the 100 micron DIRBE map against the Leiden-
Dwingeloo map of H_I emission, with corrections for the zodiacal light via a
suitable expansion of the DIRBE 25 micron flux. For the 100 micron map, no
significant CIB is detected. In the 140 micron and 240 micron maps, where the
zodiacal contamination is weaker, we detect the CIB at surprisingly high flux
levels of 32 \pm 13 nW/m^2/sr at 140 micron, and 17 \pm 4 nW/m^2/sr at 240
micron (95% confidence). This integrated flux is ~2 times that extrapolated
from optical galaxies in the Hubble Deep Field.
  The primary use of these maps is likely to be as a new estimator of Galactic
extinction. We demonstrate that the new maps are twice as accurate as the older
Burstein-Heiles estimates in regions of low and moderate reddening. These dust
maps will also be useful for estimating millimeter emission that contaminates
CMBR experiments and for estimating soft X-ray absorption.
