This is the 5th issue of my ThriftStoreConfidential Guides. The subject is valuable books. I have always loved books. So It was only natural when I began collecting professionally, I would grafitate to the thrift book shelves, library stacks, and estate sale cardboard boxes. Over the years, I have found many wonderful books at thrift stores (yes), estate sales, yard sales, even free some in the library giveaway pile. My best finds were a number of vintage 1st editions at a house sale - including Truman Capote, William Faulkner, Dorothy Parker, and so on. But I have also found great collectible books at the thrift stores  and estate sales- including many sought-after books that might not seem highly collectible. Among these: 1)  1st edition or early printings of Alcoholics Anonymous books - or other 12 step programs (the key here is the 1st edition/early printing). There is worldwide demand for AA 1st editions. 2)Also - early, pre-1930 books with their jackets intact (now, that's a hard request), because most books I see are jacket-less, or the jackets are in tatters. But true, serious collectors want a book in as near-to-pristine condition as it was when it was published. This type of book w jacket will bring the most money, of course. But 1st or early additions by famed authors, jacket-less, will also sell - although for not as much.  Also 3)- unsigned and signed 1st editions of famed writers, artists and  sports heroes. Several years ago, I ran across a 1st edition of a Bobby Jones book (unsigned). I admit I didn't know what I had (I later learned how rare it was) - and in fact, several potential buyers wrote me asking for the copyright date publisher, etc (information you should always include). I sold the book on Ebay, but greatly under value. Now, in my treasure's pile, I have a signed baseball great book from the late 1940s. Now I hedge a bit on relating this, because I haven't had the book verified by an autograph expert. I have researched many times trying to find an identical copy and also verify the signature - to no avail. The caveat is that the signature is in blue ink - the only blue ink in the entire book. And that was going to be my next point. Many of us get fooled by the automatic pen signatures of the rich and famous that grace the books we buy. In my experience, one way to ascertain an authentic signature is if it is in a different ink color than the text of the book; it it is scrawled in thick  (sharpie-like) pen and features a smudge or two, and also, if there is a salutation. I recently sold a lovely art book, signed twice by the famous, young artist - in 2 different inks and on 2 different pages. Yesterday, my neighbor showed me a "signed" Elton John on a vintage songbook. But alas, I had to tell her it was not a true signature - just a printed  automatic pen. You can research book signatures on the internet (try flatsigned.com) and also rare book values in many popular collectors books. I have them near my desk, but rarely consult them. They are good for schooling you in what authors to look for, but the price guides don't hold up very long. So, yes, you can tell a book by its cover (especially if it's not torn or price-clipped), and No, many times, a rare antique book has no cover (like the Mark Twain 1st edition  I recently sold). I've heard that books are hard sells on Ebay, but I'm not sure that's true. You will have a much easier time selling a book, however, if there aren't 10 more like it that are listed. To see what I am presently offering, and if I am following my own advice, please check out my store,  The ArtBooktique. Thank you.