Libby indicted on five counts: (2) perjury, (2) false statement, (1) obstruction of justice.   

Here’s the Libby indictment in case you haven’t already seen it. 

Libby resigns. 

Fitzgerald says the probe is not over.

But it’s clear that Libby himself was the leaker.  Fitzgerald couldn’t indict him, it seems, because Fitzgerald would have to prove that Libby knew the information was classified at the time he leaked it (mes rea for all you law students).  How do you prove what someone knows?  It’s very hard.

That’s all you need to know for now.

Seriously, don’t try to digest this too fast.  Chew everything 20 times before swallowing.  You are going to be hearing a lot about this everywhere for a long time.

UPDATE:  Okay, I lied.  but Kevin Drum has a really succinct "indictment primer", which I share:

INDICTMENT PRIMER….The two false statement charges are these:

• Libby told the FBI that Tim Russert told him about Valerie Plame on July 10 or 11. He also told the FBI that he was surprised to hear this from Russert. This was a lie: Russert never told him this, and Libby knew about Plame’s status long before that in any case.

• Libby told the FBI that he told Matt Cooper on July 12 that reporters had told him about Plame, but Libby didn’t know if it was true. This was a lie: Libby actually confirmed "without qualification" to Cooper that Plame worked for the CIA.

The two perjury charges revolve around the fact that Libby made the same misstatements to the grand jury. The obstruction of justice charge is based on the false statement and perjury charges. Taken together, they amount to obstruction of justice.

Basically, the charges are that Libby consistently tried to mislead both the FBI and the grand jury about how he had learned of Plame’s status. On multiple occasions he told investigators that he had learned about it from reporters in July, but the truth was quite different. In reality, Libby actively sought out information about Joe Wilson’s trip to Niger starting in late May, learned from both State Department and CIA sources in early June that Wilson’s wife worked at the CIA, and received the same information from Dick Cheney shortly after that. Libby subsequently discussed Plame with quite a few people within the White House, at one point admitting to his deputy that "there would be complications at the CIA in disclosing that information publicly," an indication that he knew perfectly well that the CIA didn’t want Plame’s status disclosed. He later told Ari Fleischer that the fact that Joe Wilson’s wife worked at the CIA was "not widely known."