Medical reference books: keep until a new edition appears.
Critically-acclaimed novels: if read, keep for kids. If not read despite sitting on shelves for 5 years (the “five year rule” it goes to charity.
Theology books:: if a book moved me enough to make significant changes in my thoughts and behaviors, I keep it. For example, “Into the Depths of God;” “The Divine Conspiracy;” “The Jesus Creed;” “Surprised by Hope;” or “Pagan Christianity.” If merely interesting or educational, I pass it onto libraries or charities so someone else can benefit.
Trash novels and superficial theologies don’t even make it past the door (so we pray).

I’m afraid we’re terrible book hoarders – both fiction and non-fiction. If I think there’s a possibility I may want to read a book again any time in the next, say, 10 years, I’m loathe to throw it or give it away. This does create a problem with space, though. With a house move coming up, I think we’ll have to take the opportunity for a major sort-out.
Thinking back to my childhood in the 70s, my parents didn’t have this problem because the vast majority of books they read came from the library. I can’t remember the last time I got a book out of the library (I say this not with pride). There’s been a big change in culture.

Whenever I move house (which is fairly frequently), I assess my books.
Books I’ve read and would recommend to friends, I keep. Books I don’t think I’ll ever read again or lend to friends, I give to charity shops – although I sometimes keep them if they have sentimental value (the first book I recall buying, a gift from a loved one etc).
For books I haven’t read, I try and figure out why I haven’t read them yet, and sometimes give to charity if I realise I don’t actually want to read them.
And sometimes I give books away because I think someone else will value them more than I do.

My wife and I are big-time hoarders. The only time we’ve given away large numbers of books was when we got married, and had to prune out the (many) duplicates.
If there’s any chance I’ll read it again, or want to look something up in it, it gets kept. Plus, they just look so darn cool on the shelf. Sometimes we’ll give some away if they were required for school and we have zero interest in them. But mostly we keep them, just in case. I think we make up for it by being generous about lending books to friends and family, which of course frequently turns into a “gift” when people forget to bring them back.

Yes. We still have our college textbooks from thirty years ago. We only culled/cull duplicates.
Our daughter, taking AP English had a long reading list to choose from one summer – and was amazed to find that we had a significant percentage on the shelf.
But we do use libraries heavily as well – both community and University.
Most “culled” book wind up as landfill or in an incinerator. Unless they are truly trash – or of value to a library (most donated books are not)- or marketable as used, it makes more sense to me to keep them in our (home) library.

My favorite books religious/spiritual books, I re-read every few years. It is amazing how much more wisdom and inspiration I find in them, they never get old. I keep all of my reference and art books. I have given most of the children’s books to the grands but I still have 5 bookshelves crammed full. Just reread all of my John Steinbeck collection. Everytime I want to get rid of a book, I reread it – then decide, Hmmmmm I’m a hopeless case!

I use similar criteria as Mike M. However, living in intentional community, I keep more and share a lot. A great place to start learning sharing things in common as a community.
Peace,
Jamie

Keep ‘em all is basically the approach here. I try to prune out lame theology during the buying process, so that’s why you won’t see John Piper on my shelf. ;o)
And, yes Scot, my books are piling up like the national debt. But I think the only way to make my collection smaller is by purchasing MORE books – it’s the book stimulus package!

For years I took great pride in the size of my theological library — and the space it took up in my office. And then, a dozen or so years ago, during a building expansion I had to vacate my office for about a year and move into what can only be generously described as a large closet with one bookcase. All my books that couldn’t fit on that one bookcase had to be packed away and stored in a garage. This was going to be the most painful year of my life!
But I culled out the best commentaries and reference books and dutifully packed away the rest. What I discovered during that year was that I hardly missed most of “the rest” that I had packed. Two times during that year I wanted one of those stored books (and managed to do just fine without them!).
As a result of that experience, I instructed our contractor to cut the shelf space in my new office in half. I then unpacked a number of the books that I had stored away but left most of them in their boxes. I then took a dozen or more large boxes to a presbytery meeting (where the young guys thought they were a gold mine!) and gave them away.
Finally, I instituted a policy that I had to make space for any new books by getting rid of an old one. Some I’ve brought home (sort of cheating!), but most I have donated to our church library, sold, or given away. Amazingly, some of the older relatively obsolete ones I’ve actually (painfully) thrown away!
More recently, as I have thought about retirement (at least another 4 or more years away, Lord willing!), I’ve begun to cut even deeper, culling some of the books that are worthwhile but that I haven’t used in ages. There are some sentimental favorites, of course, that my kids will probably have to throw away; but in the process I’ve learned that a good library is deeper than it is wide.

We have found the public library here loves to get books given to them. Ours will also give you a letter for taxes. Nice help!

My newest strategy is to sell enough books on Amazon to enable me to buy a Kindle. So a season of purging will lead to longer season of electronic collecting and hoarding — without the guilt-inducing sight of over-packed bookshelves.

Well, books that have deeply impacted me and/or that I think I either may read again or reference, get kept. Books that I find to be a total wash in the past I sold online. Lately, with the economy, I’ve bought a lot less books and am using the library more (a sure way not to become a pack rat)!

Books that I am certain I will never refer to nor want to refer someone else to are all thrown away. That is not a large set!

Prune books? Cull books?!?! Dear God, man! I remember the years we lived in Houston. I had a loft built over cinder block shelves of my Dad’s library. Today, I sit in an office surrounded by overflowing bookshelves. There is something comforting about having books I have read around me. A book has to sink pretty low for me to get rid of it. More than just being something I probably won’t read again, it has to be something I actively disliked. Other than that, it’s mine forever — except for those I loan to others. It’s hit or miss whether or not they ever return.
My wife feeds my book habit in a controlled manner. For gifts at major occasions I tend to get book store gift cards. Ah. Browsing among the stacks of books. Picking out a stack to sit and skim as I drink coffee. Pure heaven. But when I don’t have a gift card I’m restricted from bookstores. I do buy specific books that I already know I want to read online. It’s a loophole.

Well, first I’ve got to be in the right frame of mind. (An upcoming move has often been an impetus, as well as shelves that are so full I can’t keep them organized….) Then I usually just look at them and decide. There isn’t much science to it, really just a feeling that realistically I’ll never want to look at it again, and off it goes.
I’ve bought more books since arriving in Texas a couple of years ago. When we lived in Grand Rapids, I could get almost any Christian book I was interested in from the library. Here it’s almost impossible. So, I buy and read. (I’m so thankful for Half Price Books!) If I don’t keep them they go either to the library’s donation pile or I swap them on paperbackswap.com.

My parents left me a house full of books to deal with–I gave away about 40-50 large boxes of their books and only kept a very few to treasure–that made me go home and prune my shelves–I’ve tried to make that a rule that whenever my shelves are full–some have to go.

I was looking for a Pack-Rat moving container and I found myself here. And now I’m thinking how do I go through all my books and sell most of them instead of saving them. And who takes old tapes and video anymore? I am getting to old (60) to keep all this stuff. When your grandchildren want you to put everything on DVD or CD it gets tiring