As an "introduction to ancients" I recommend the series of books by Wayne G Sayles, "Ancient Coin Collecting" put out by Krause. There are six volumes, covering Greek, Roman, Roman Provincial, Byzantine and "Other" ancient civilizations. These books give an excellent overview of the "look" of coinage from each place and time, and should help in narrowing down any search for a particular artistic style.
If you want a more detailed reference for each series, try the Sear catalogues. They're not cheap, but are much more comprehensive that the Sayles books, which aren't intended to be "catalogues".
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis