He did realize that ethics are objective (unlike epicureans), but he did not connect them to a source. I'm not criticizing him, just pointing out a simple fact. Ayn Rand objectivists do the same thing! They say certain objective ethical rules exist - but can't name the source! In that sense, Socrates was like Ayn Rand, but the similarity ends there. Ayn Rand has no personal or sexual morals from what I understand, and her ethics were quite compartmentalized. At least Socrates ethics covered a wider spectrum of the human existence.
It scarcely begins. Socrates claims ignorance, which is something Randians will never do and objectivists forget to do. Skeptics and rationalists have a few things in common--like sneezing and such.
Read him. The source is divine.