This is John Dagys excellent resource guide for the race. The race itself takes place the 22nd to the 23, but of course there are many events prior. Scutineering starts today and runs through tomorrow. John's guide provides links to live timing, overall schedule, TV schedule, weather, etc., as well as highlights from last year's race. Keep it handy if your a fan of the 24 LM.
Edit: Since the official 24 Hours of Lemans site and Twitter feed is tagging everything with #LM24, I will use that tag also on Twitter. For here, LM 24. The drivers seem to be having fun with the Twitter mirror.