  We have combined data from the NOAO Deep Wide-Field Survey in Bootes and the
Spitzer Space Telescope to determine basic properties for sixteen optically
"invisible" MIPS 24um (OIMS) and thirty-five optically "invisible" radio (OIRS)
soruces, including their spectral energy distributions (SED) and luminosities.
Most OIMSs possess steep power-law SEDs over lambda(rest) = 1-10 um, indicating
the presence of obscured AGN in agreement with Spitzer spectroscopy. These
objects are extremely luminous at rest-frame near and mid-IR (nu L_nu(5um) ~
10^{38}-10^{39} W), consistent with accretion near the Eddington limit and
further implying that they host buried QSOs. The majority of the IRAC detected
OIRSs have flat 3.6 to 24um SEDs, implying comparable emission from stellar
photospheres and hot AGN illuminated dust. This may reflect relatively small
amounts of dust close to the central engine or current low mass accretion
rates. A small subset of OIRSs appear to be starburst dominated with
photometric redshifts from 1.0 to 4.5. The OIMSs and OIRSs with significant
starburst components have similar L_K and stellar masses (M* ~ 10^{11} M_solar)
assuming minimal AGN contribution. Roughly half of the OIRSs are not detected
by Spitzer's IRAC or MIPS. These are most likely z > 2 radio galaxies. The IRAC
detected OIRSs are more likely than OIMSs to appear non point-like in the 3.6um
and 4.5um images, suggesting that interactions play a role in triggering their
activity. The AGN powered OIMSs may represent sub-millimeter galaxies making
the transition from starburst to accretion dominance in their evolution to
current epoch massive ellipticals.
