Resources for Classicists and Students of Ancient Greek
Typegreek.com for web-ready polytonic Greek.
The Perseus Collection: A resource of classical texts and translations, including the Liddell-Scott lexicon. Not quite the complete corpus, but a damn fine resource.
The SPIonic font I used before discovering that web browsers couldn’t actually read it if they didn’t have the font (contrary to what the distributes of the font advertise), but it works GREAT in your word processor.