I recently had a sort of similar experience, except mine went South way more than yours did.
Someone recommended to me the book, The Legal Handbook for Photographers. I bought it, and can't recommend it enough. If you're concerned about what you're taking pictures of, and how people will react, that book is money very well spent.
And yes, you have every right to stand on the sidewalk and take pictures of peoples' houses in the US.
There's a really cool book I was looking through in a hotel lobby in Boston. It shows all the old buildings before they were destroyed or remodeled. I can't remember the name specifically
I believe it was this book: https://www.amazon.com/Lost-Boston-Anthony-Sammarco/dp/1909815047/ref=pd_aw_vtp_14_2/144-1991690-0572464?_encoding=UTF8&pd_rd_i=1909815047&pd_rd_r=975ee278-681b-4183-b49b-70bd4c054d14&pd_rd_w=BDZiO&pd_rd_wg=8oliw&pf_rd_p=508558...
A danish book. This one from Amazon
Danish stamps. "Frimærker" And the special xmas stamps called "Julemærker".
https://www.julemaerket.dk/ (only in danish sorry)
If you like these, there's a book called Indianapolis Then and Now that compares the historical photos with their modern day locations: https://www.amazon.com/Indianapolis-Then-Now%C2%AE-Nelson-Price/dp/1910496588
We enjoyed it thoroughly. It was bike paths the whole way with only a few hundred meters of exceptions when moving from one path to the next one. I bought this book a few years back:
https://www.amazon.com/Epic-Rides-World-Lonely-Planet/dp/1760340839
Epic Bike Rides of the World 1
And that is my slightly modified version from one of those "Rides".
Definitely a good resource: https://www.amazon.com/Legal-Handbook-Photographers-Liabilities-Selling/dp/1682032868
It is on Amazon and a bit cheaper? I believe I paid $25
Colour: Travels Through the Paintbox - Victoria Finlay
She travels the world exploring the various historic means of acquiring each major colour pigment. It's a fascinating read; even for people who don't paint.
No real tips, or inspiration, but I saw this book in a store a few months ago and thought it was really cool!
Epic Rides of the World by Lonely Planet: https://www.amazon.com/gp/product/1760340839/ref=ox_sc_saved_title_8?smid=ATVPDKIKX0DER&psc=1
They have others for hikes, and such too.
I'll second this. Although it may be too satirical at some points, where you have to know how Danes actually act in certain situations.
Also here's a link: https://www.amazon.com/Xenophobes-Guide-Danes-Helen-Dyrbye/dp/1906042276/ref=sr_1_1?ie=UTF8&qid=1469127772&sr=8-1&keywords=xenophobes+guide+to+denmark
If you like odd twon names, you would also like this boo, Reaching Climax SFW. It is a collection of dirty sounding town names