When researching a project, as well as Googling yards and yards of stuff, I am also up to my ears in books. They are mostly 'special orders' from the library - I commend this to you. I do buy the occasional book but I have to know it will be useful because, like everything else in my life, I am not a hoarder; almost without exception once they are read they are 'finished with' and charited. (yes, that is a Marilyn verb)
Trevor Yorke has written a great series of books each of which is a really sound starting place for any period house you want to do. I bought his Georgian and Regency book for my iPad as a portable quick reference for most things.
The next (keeper) book came from a lady who's three blogs I follow. Her work is just jaw-droppingly good and an inspiration for people like me. Here is a link to one of her blogs, Netherton Hall, you can find her other two from there. She was so kind and just sent this to me because she knew it would be useful. I am going to see this particular Edinburgh house next month. My treasured book will go with me.
My third keeper is just crammed with utter detail and because it is primary evidence of life in my sort of house I really enjoy it. Better still, it was an absolute bargain. I found this on Amazon having read about it somewhere and it cost one penny plus postage, so it cost me the grand sum of £2.81. Looks like a dense read but it will keep me busy while the glue dries.