i would learn latin as it is the language all romance languages are derived from so theoretically it would make it easier to learn languages such as italian, french and spanish. It is also good for understanding english grammar. Up to you though, learning hebrew would be cool too
try rosetta stone. ive actually used rosetta stone latin, and its pretty good. i dont know if rosetta stone has hebrew, but hey, go for it. and, btw, rosetta stone costs like, $700. i got it from the library.
cambridge latin coarse website :)