It doesn't have to cost hundreds of pounds, and you don't have to buy dozens of copies to store in your garage. Both Lulu and PABD will do this for you for little more than the cost of the book, give or take a nominal setup fee:
http://www.lulu.com/uk
http://www.pabd.co.uk/
I wouldn't normally recommend Lulu, because they're American and don't have much of an idea about publishing for the British market, but since you're not intending to sell the book, then there's no reason why you shouldn't use them. Their finished products are pretty good, by all accounts.
You may be interested in Bob Trubshaw's 'How to Write & Publish Local & Family History' (ISBN 1872883591). It is an extremely informative and comprehensive book that deals with everything from initial research right through to marketing the finished project, and includes a few basics about copyright, photographs and typesetting as well.