Having a bit of a clearout.
Some old tech books (mainly SQL2008), if you want one and are prepared to pay postage you can have one! Excellent condition. Else they are bin bound.
Cheers
why not keep them in the office in a bookshelf and show your competence 
take them to charities shop or like i do, take it to homebase. over in wimbledon, their have a book shelves at the place and we bring lots of book to donate… and it is better than going to the bin.
most of mine is either ibook or kindle… on my iPad mini
tried that - no-one believed me 
can’t imagine many charity shops having much use for this kind of book.
you never know… charity shops might not be the right place… we put in some MS Access book and it disappear after a while.
A few years ago I had a large general library I wanted to donate, I called charities in Paris, and none wanted any book. Not even public libraries.
And now computer books start disappearing from the shelves in bookstores. We had two computer bookstores, one has closed down. I am afraid at a time when politicians go out saying that kids should learn coding at school, the computer culture has so dramatically shifted, paper books are quick becoming a legend of the past.
Ah but you can learn anything on the internet so who needs books ? 
so long as you trust the source
I went to a german computer shop (Fun Computer) in Kehl last week and park my car near a square. They had small bookshelves for people to take, read and eventually get them back, free !
I knew that before because I read about it in the newspaper, but (like many things) I forgot. I was astonished to see that, then I recall.
BTW: the first 15 minutes for the car park are free, but you have to get a ticket !