If you're after a book - Joe Friels books ( The Triathletes Bible and Going Long) are both good although very, very detailed. Going Long is definitely IM oriented but still helpful to read. Another book/site is Chris Carmicheal, The Time -Crunched Cyclist . Obviously, its only about cycling but the program is a pretty good fit for Oly - half IM distance racing and has very specific plans laid out for you. Carmicheal is Lances coach ( which you may or may not like....works for me) and has some very good basic knowledge about training and nutrition included in the book. I've learnt a lot from all these books.

I'd also recommend the articles and forums on slowtwitch.com . These guys have been tri-obsessed longer than most and their sense of detail seems to know no bounds.

However, you'll need to work through all of these resources to find specifics for Olympic distance. Please post any good finds - this is the distance that I'm chasing this season too.