  We report on the results of an optical spectroscopic survey designed to
confirm the youth and determine the spectral types among a sample of young
stellar object (YSO) candidates in the Serpens Molecular Cloud. We observed 150
infrared excess objects, previously discovered by the Spitzer Legacy Program
"From Molecular Cores to Planet-Forming Disks" (c2d), bright enough for
subsequent Spitzer/IRS spectroscopy. We obtained 78 optical spectra of
sufficient S/N for analysis. Extinctions, effective temperatures and
luminosities are estimated for this sample, and used to construct H-R diagrams
for the population. We identified 20 background giants contaminating the
sample, based on their relatively high extinction, position in the H-R diagram,
the lack of Halpha emission and relatively low infrared excess. Such strong
background contamination (25%) is consistent with the location of Serpens being
close to the Galactic plane (5degrees Galactic latitude). The remaining 58
stars (75%) were all confirmed to be young, mostly K and M-type stars that are
presumed to belong to the cloud. Individual ages and masses for the YSOs are
inferred based on theoretical evolutionary models. The models indicate a spread
in stellar ages from 1 to 15 Myr, peaking at 2 - 6 Myr, and a mass distribution
of 0.2 to 1.2 Msun with median value around 0.8 Msun. Strong H emission lines
(EW[Halpha] > 3 A) have been detected in more than half of the sample (35
stars). The mass accretion rates as derived from the H line widths span a broad
distribution over 4 orders of magnitude with median accretion rate of 10^-8
Msun/yr. Our analysis shows that the majority of the infrared excess objects
detected in Serpens are actively accreting, young T-Tauri stars.
