The bigger charities now often have actual bookshops, or have special displays of books – Dorothy House have a big bookshop in Bath*, their small shop in Chippenham has one window set aside for books, the RSPCA shop opposite has a ‘collectors corner’ for comics, SF books, etc. While you may not get rid of all of them to one outlet, dividing them into more easily swallowed batches means you may shift them quicker.
*I was walking past one day and spotted a big book about Pink Floyd, written by Nick Mason, the drummer. He opens his gardens up for charity and has a load of his cars on display, and is usually wandering around, so I took it along and asked if he could sign it; “bloody hell, where did you find that?”, in a Bath charity shop, I told him. He was more than happy to, and he signed my CD of his band’s gig at the Roundhouse, in London. Seeing him again in Bristol later this year as well. He lives between Chippenham and Bath, and has been seen shopping in Sainsbury’s, driving his Ferrari 250GTO.
As one does…