  This is the first paper of a series in which we present new measurements of
the observed rates of supernovae (SNe) in the local Universe, determined from
the Lick Observatory Supernova Search (LOSS). We have obtained 2.3 million
observations of 14,882 sample galaxies over an interval of 11 years (March 1998
through Dec. 2008). We considered 1036 SNe detected in our sample and used an
optimal subsample of 726 SNe (274 SNe~Ia, 116 SNe~Ibc, 324 SNe~II) to determine
our SN rates. This is the largest and most homogeneous set of nearby SNe ever
assembled for this purpose, and ours is the first local SN rate analysis based
on CCD imaging and modern image-subtraction techniques. In this paper, we lay
the foundation of the study. We derive the recipe for the control-time
calculation for SNe with a known luminosity function, and provide details on
the construction of the galaxy and SN samples used in the calculations.
Compared with a complete volume-limited galaxy sample, our sample has a deficit
of low-luminosity galaxies but still provides enough statistics for a reliable
rate calculation. There is a strong Malmquist bias, so the average size
(luminosity or mass) of the galaxies increases monotonically with distance, and
this trend is used to showcase a correlation between SN rates and galaxy sizes.
Very few core-collapse SNe are found in early-type galaxies, providing strong
constraints on the amount of recent star formation within these galaxies. The
small average observation interval ($\sim 9$ days) of our survey ensures that
our control-time calculations can tolerate a reasonable amount of uncertainty
in the luminosity functions of SNe. We perform Monte Carlo simulations to
determine the limiting magnitude of each image and the SN detection efficiency
as a function of galaxy Hubble type ... (abridged)
