I wrote a beginner's guide to prints by the masters-- ala rembrandt to chagall. Gives the basics to intelligent buying. The usual basics of 'do your homework' and 'buy from good sellers' applies to this area of collecting as all areas of collecting . . . One positive thing for potential collectors is famous artists' prints are well researched and documented by art history professors, curators, etc and a potential buyer can look up to see if a particular print matches up with known originals (size, type of printing, papermark, numbering, etc)-- including whether or not it should have the artist's signature. At the very least, this allows the beginner to double check a seller's claims about a print.
Also, as I say, being a forgery doesn't mean it's a good forgery. Most buyers of these fakes have little knowledge or experience in the area, and just believe whatever the seller tells them. And the scammers in most any area make their money selling to the ignorant and gullible.
prints' guide