  The remarkable uniformity of Type Ia supernovae (SNe Ia) has allowed
astronomers to use them as distance indicators to measure the properties and
expansion history of the Universe. However, SNe Ia exhibit intrinsic variation
in both their spectra and observed brightness. To reduce these systematic
uncertainties, we need a deeper understanding of the observed variations in SNe
Ia. Toward this end, the Nearby Supernova Factory (SNfactory) has been designed
to discover hundreds of SNe Ia in a systematic and automated fashion and study
them in detail.
  A prototype run of the SNfactory search pipeline conducted from 2002 to 2003
discovered 83 SNe at a final rate of 12 SNe/month. A large, homogeneous search
of this scale offers an excellent opportunity to measure the rate of SNe Ia.
This dissertation presents a new method for analyzing the true sensitivity of a
multi-epoch supernova search and finds a SN Ia rate from $z\sim0.01$--0.1 of
$r_V = 4.26 (+1.39 -1.93) (+0.10 - 0.10)$ SNe Ia/yr/Mpc$^3$ from a preliminary
analysis of a subsample of the SNfactory prototype search.
  Several unusual supernovae were found in the course of the SNfactory
prototype search. One in particular, SN 2002ic, was the first SN Ia to exhibit
convincing evidence for a circumstellar medium and offers valuable insight into
the progenitors of SNe Ia.
