Greek coins are considered by many to be the pinnacle of ancient numismatics. The earliest documented coins are from the Ephesian Artemission finds of 1904-05. They were lead by the British Museum's D.G. Hoggarth. Recommended reading is E.S.G. Robinson's 1951 article from JHS, "Coins from the Ephesian Artemission Reconsidered." I do not have this article in my library right now, but it's on my list of things to get.
There are many areas, regions and cities to collect, so a comprehensive collection of Greek coins would be exceptionally large. I don't have many Greek coins yet, but I will add pages as my collection grows over the years.
Notes from Phil Jones, archaic Greek specialist, received on June 19, 2006: "There was a very famous conference as well, just before Martin Price passed away, on the Artemission finds. Price's attribution of the hoard to a later date has since been debunked, but I still found it worth while to read.
It's important to note as well that Croesus was not the first Lydian King from the Mermnadae Dynasty to have produced coins en masse. Alyattes and possibly Sadyattes (though this is debated quite extensively, I tend to support the idea that early Weidauer 15 coins fall within the reign of Sadyattes.) also produced quite extensive coinage. They were made in electrum.
Croesus' coinage was in gold and silver only and went through three different reforms of weights. You can read more about this in Colin Kraay's Archaic and Classical Greek Coins, 1976, Stanford Durst."