One way to help your local library (and get great deals on books in the process) is to support the annual book sale held by the Friends of the Library in your town. And if you happen to live in a large metropolitan area, there is the added bonus of multiple sales every year, since each city has their own Friends of the Library chapter. At these sales you can find books, sometimes in like-new condition, at prices even lower than at the average garage sale.
There are a few things to know in order to make the most of a library sale, and the first is when and where they will be held. The best resource for library books sales is the website Book Sale Finder, which lists every book sale in the country by state. The site lists both annual sales and ongoing sales that some libraries have.
When researching an upcoming sale always look at the total number of books items and the percentage of donated items (this will also be listed on the Book Sale Finder site). The best sales will have at least 25,000 books; those with under 5,000 are often a waste of time. This is because the total number includes things like textbooks, VHS tapes, and vinyl records, and without a high number of total items, the number of books will be too small for a good selection.
The number of donated items is equally important, especially if you are a serious collector. Donated books are copies given to the Friends of the Library by the public. If 50% of the items are donated, that means that the other 50% are ex-library copies that have been removed from the shelves for one reason or another. While these are perfectly fine reading copies, most folks don't want a bunch of tattered, discarded library books on their shelves at home. Look for sales where at least 75% of the items have been donated.
The next thing you will want to do is check the hours of the sale. Most will start on a Thursday night and run through either Saturday or Sunday. Thursday nights are usually a "sneak peek" for those who have a membership in the Friends of the Library. Those who are not members can join at the door for anywhere from $10.00 to $35.00; it is a good way for the Friends to increase their membership and for members to have first choice of the books available. Prices for the rest of the weekend will usually be $2.00 for a hardcover book and $1.00 for a paperback. Many sales will use a sliding scale over the course of the weekend, with hardcovers dropping to $1.00 on Saturday or Sunday and paperbacks to fifty cents.
If you attend on a Thursday night or Friday morning, arriving at least thirty minutes to an hour early is essential; even then there will already be people in line. If the sale allows, you should bring an empty box or crate for the books you choose; most sales only have small plastic bags available for patrons' use. There will also typically be a map showing the layout of the sales floor. Look over this before the doors open so you can determine the best route to your areas of interest. Also, although most sales now accept checks and credit cards it is always best to bring cash just in case.
Finally, bring a large amount of patience with you. There will be a lot of waiting, both for the doors to open and during the checkout process (the books will be tallied at one table and paid for at another, and there are never enough volunteers). People will push and jostle, and it is entirely possible that a sweet little old lady will punch you in the kidney so she can get to that Janet Evanovich hardcover before you do. Such is the gentle passion of book lovers.