  We present a homogeneous survey of line and continuum emission from
near-ultraviolet (NUV) to optical wavelengths during twenty M dwarf flares with
simultaneous, high cadence photometry and spectra. These data were obtained to
study the white-light continuum components at bluer and redder wavelengths than
the Balmer jump. Our goals were to break the degeneracy between emission
mechanisms that have been fit to broadband colors of flares and to provide
constraints for radiative-hydrodynamic (RHD) flare models that seek to
reproduce the white-light flare emission. The main results from the continuum
analysis are the following: 1) the detection of Balmer continuum (in emission)
that is present during all flares and with a wide range of relative
contributions to the continuum flux at bluer wavelengths than the Balmer jump;
2) a blue continuum at flare maximum that is linearly decreasing with
wavelength from \lambda = 4000-4800\AA, matched by the spectral shape of hot,
blackbody emission with typical temperatures of T_{BB}~9000-14,000 K; 3) a
redder continuum apparent at wavelengths longer than H\beta\ (\lambda >
4900\AA) which becomes relatively more important to the energy budget during
the late gradual phase. We calculate Balmer jump flux ratios and compare to RHD
model spectra. The model ratios are too large and the blue-optical (\lambda =
4000-4800\AA) slopes are too red in both the impulsive and gradual decay phases
of all twenty flares. This discrepancy implies that further work is needed to
understand the heating at high column mass during dMe flares. (Abridged)
