So, how do I find out who actually said something?
Unfortunately, the Net, where I get a lot of my quotations these days, is no better than anywhere else about citations. In most cases — though not all — you’ll get at least the last name of the person who first crafted the quotation. Sometimes you’ll get a date range for their life. Rarely will you get the name of the work.
I’ve tried to fill in all the citation info in WIST that I can; if you have additional data or corrections, please feel free to contact me at the address in the sidebar.
The biggest problem one has in this sort of endeavor, after just plain old getting the data, is something most people probably wouldn’t think of: how to order people’s names.
For example, Fred von Smith. Is that under “V” or under “S”? If you set up a rule saying it should be “V” but everyone refers to him as just “Smith,” should that change your mind?
And there is, alas, no consensus. The two works I consulted most, Bartlett’s Familiar Quotations and my Webster’s Biographical Dictionary both came to opposite conclusions on the matter in a number of cases. They also had some intereresting variant spellings of names.
I’ve tried to take my cue from Bartlett’s. Where writers have pseudonyms, I have grouped their quotes under the more common name. The Search box should let you find where something is.
The other questionable item is nationality. Once I decided I wanted to give a little bit of biographical info on the various authors (since that provides context for the quotes), I initially took the lead from the Webster’s, which seems to use the nation in which the person eventually flourished (and or became a citizen of). Thus, Einstein was American. Later, I found that a number of places gave a mixed heritage — birthplace and flourish-place. So Einstein would become a German-American. I’ve made some changes based on that practice, but I’m not yet consistent.
Okay, one other possible stumbling block. Who actually said something? This can take a number of forms:

• A citation says “Jones,” with no other reference as to which Jones actually said it. This is relatively rare. Sometimes the name is so famous (Hawthorne, Melville), it’s obvious. Other times, it’s a crap shoot. A related problem is two people with the same name, but at different periods, who could have said something (the two Oliver Wendell Holmes, Senior and Junior, for example, or the two Senecas). I’ve made my best guess at this, but welcome any corrections.
• Did the person to whom a quotation is attributed actually say it? Or were they quoting somebody else? The more general the aphorism, the more people who may have said it (the record that I’ve found is five distinct names attributed to a particular quotation). Did they all say it? Were they quoting a common source, or coming up with a similar idea independently?
  And, of course, there are problems with possible misspellings of attributions. I have a citation for a quote that says it was made by Fred Jonson. Nobody by that name in Webster’s, but there’s a Fred Johnson in there. Was the attribution a typo? Do I look like an idiot for changing the citation, or look like an idiot for leaving it as is?

When it comes to names, the other issue is how much of the name to put in. If someone has many given names (Winston Leonard Spencer Churchill), should it be cited as such? If someone is usually known by the first initials (H. L. Mencken), should I spell out those names? If someone is commonly known by their middle name (John Calvin Cooledge), is there value in giving the first name? I’ve made a number of choices here, trying to reach a balance between accuracy and still having the person be recognizable. Your mileage may vary. Mine certainly does each time I go through this exercise.
Given that I don’t have a wide array of biographical tools to exhaustively research every individual, and that I’ve grabbed the quotes where I can, sometimes the name listings are a little slim, missing dates, even first names. If you know who is being referred to there, please write me and let me know. (I would say, conservatively, that it takes me as much time to research and update my author biographies as it takes me to gather the quotes in the first place.)
One place I’ve found to search for biography is (surprise!) on the Net. It’s by no means a sure thing, and the tendency of quotations (complete with errors and misattributions) to be passed around the Web like monks passing along typos from copy to copy is certainly a barrier to good scholarship.
I’d say that WIST is one of the better-researched sites, but I acknowledge that the level of confidence in attributions should be placed somewhere around a high school senior paper.
That having been said, a few particularly good places on the Web to research:

• The Dead People Server (it has live people, too)
• The Biographical Dictionary Search Page
• Biography Find
• The Internet Movie Database (good for movie and TV personalities; also a good source itself for quotations)
• The McCain Library Online Catalog (library catalogs often include author born-died dates, as well as dates for the works themselves.)

Or, of course, you can just do a Google search for the name (searching both “Firstname Lastname” and “Lastname, Firstname” often gives different results). That’s what I did this most recent pass for all the names I couldn’t find otherwise.
Sometimes, when not able to find anything about “Reginald Knickerbocker,” I’ve found doing a Web look-up on the quotation is sometimes productive. You may find that the quite is attributed to “Reg Knickerbocker” (about whom you can further research). You may also find that the quotation is actually attributed to Hyman Fernly, which is valuable information in and of itself.
Some people can’t be found, at least through the Web. Since this is not my Real Job, I don’t have time to do more research than I do, but it’s still a bit disconcerting when the only thing on the Web about Hyman Fernly is that he uttered a particular sentence. It does make one wonder.