Not everyone in the genealogy business is worth dealing with. There are plenty of scams, hoaxes and bad deal out there. Be aware of these common ones.
Though genealogy may seem like a harmless and reasonably friendly sort of hobby, that doesn't mean there aren't people out there hoping to cash in your family tree interests. Be aware of some common scams and hoaxes so that you don't get led down the wrong path in search of that next ancestor.
Books supposedly written all about your specific family surname are a very common scam, and the easiest to fall for. Books titled "The Smith's of the World" or "Yearbook of the Smith Family" are close to useless and not worth your money.
These books will contain only the barest and most general history of your surname, a "crest" that may or may not have any actual association with your family (see below for the family crest scam) and there will usually include a huge section of people supposedly in your family. These section may seem worthwhile, until you realize that it's simply pages from phone books and directories. Knowing there are 19 people named "M. Smith" in your family is pointless without further details.
Most legitimate family history books cover entire lines of families, and will include a number of different surnames. Or they may contain family information relevant to a particular region. Books are just not usually published for one single surname.
This one is frustrating because the principle is flawed in the first place. Coats of arms were never granted to families or by surname, they were given to individuals who then passed them on to a single child in the next generation. There is no such thing as a family crest, or a family coat of arms. Anyone trying to sell you a lovely plaque or other item with your family crest on it, isn't offering anything legitimate.
This scam can be harder to spot, especially these days with such a burst of online resources for genealogists. Some unscrupulous people will set up genealogy websites that are accessed by paid subscription, only to provide you with links and information based on other free sites. Basically, they are providing for you (at a cost) the same information you could easily access yourself for free.
And this isn't a case of paying someone else to do lengthy research to save you time. Most of these places link to huge online databases like Rootsweb and Familysearch.
These sites tend to come and go quickly, so it's difficult to provide any warnings. Past culprits have been genealogygiants.com, genlocator.com and genseekers.com. None of these sites are currently still in operation, to my knowledge. If a site offers no way to contact the operators, or their emails come from a disposable account like Hotmail or Yahoo!, then you might want to be wary about them.
This is probably the least likely scam you will come across, but worth mentioning nonetheless. If you plan on hiring someone to do research for you, make sure they are officially recognized as a professional genealogist. They should be listed with the Board for Certification of Genealogists, or at least a member of the Association of Professional Genealogists.
Anyone can claim to be a pro, and then charge you for "research" that may be poor or even non-existent. As with even professionals, you pay for the person's time not results. With a shady individual, they may not do any work and still bill you for it.
This isn't to say that anyone NOT accredited by the Board for Certification of Genealogists must be a scam-artist. But you are taking a bit more of a risk by hiring someone without some form of professional credentials.