It was part of the color coded war plans. The British empire one was war plan red, Germany black, Japan orange etc as well as a bunch of other scenarios like problems in Mexico or Cuba. Basically red found that the British would have an upper hand and use Canada as a staging ground for invasion but eventually the US would win. Plan Red-Orange (Uk and Japan) found that USA was not prepared for a two ocean war and should focus probably on the Atlantic and not the pacific. Which is exactly what the US did in WWII, with the obvious exception of the different enemy.

The US primarily wanted to capture Halifax and then occupy the important parts of Canada. The British plan did not want to dispute this. From their they would concentrate their fleet in the Atlantic, but had no plan to attack Britain or British trade before they could fight a fleet battle in a favourable position. Should the Brits not do so, their was little other planning of how to conduct the war.

I don't know of a book, but there is a paper called 'Thinking the Unthinkable: British and American Naval Strategies for an Anglo-American War, 1918-193'.

As general background every military has (or at least should have) plans for every possible variation of who might attack and who might be attacked. So you can find some pretty odd stuff in the archives.

One example, mentioned above in passing, was the plan for the US to invade Canada in 1939, if the Nazis should invade the UK.

I don't know if you do this in the US but in the UK on 1 April the newspapers all try to run a story which is nonsense, an April Fool. One year the Telegraph (a major broadsheet newspaper) ran the story that the US had had plans to invade Canada in 1939. Everyone leapt to the conclusion that that was the Fool story for the day. Except, of course, it was a reverse Fool because all militaries always have plans for that sort of thing.