The DNA HIV vaccine VRC-HIVDNA009-00-VP has shown immunogenicity in multiple clinical trials; in one trial, the DNA vaccine demonstrated a nearly 100% CD4 T-cell response rate. The adenoviral vector HIV vaccine VRC-HIVADV014-00-VP has shown immunogenicity when given intramuscularly and has appeared safe and well tolerated in prior vaccine trials in HIV uninfected adults. The DNA plasmids in both vaccines code for proteins from HIV subtypes A, B, and C. This study will evaluate the safety, immunogenicity, and tolerability to a DNA HIV vaccine, followed by an adenoviral vaccine boost given either intramuscularly, intradermally, or subcutaneously, in HIV uninfected adults.