This is a handbook written for college students, but which is also cited by scholars in the field. It is very good. It is also short and can be read in an afternoon. It presents a clear and concise account of ancient greek religion, and is intended to clear away the many misconceptions that people have about the topic. Greek religion, as actually practiced, had nothing at all to do with the gods of Homer, which were a literary construction (they serve in Homer as a foil to point the contrast to our mortality) -- and a late one at that, with belief systems (-- there is no way in greek to say: "I believe in", nomizein
meaning simply "to hold in honor", cognate with nomos
= 'law' or 'custom'), or any such thing -- but was a religion (religio
) of prayer and sacrifice rooted in the presuppositions of sympathetic magic.
For those who haven't the time to plough through de Coulanges or Frazer, this is a great place to start.
Let me add here what I said elsewhere today: Lafcadio Hearn's book on Japan:
is one of the best books I have ever read on ancient *greek* religion.