Outlining new book idea

I've been outlining the new idea I have for a book for family caregivers - still trying to decide if I am on the right track with it or not, but it's looking okay so far. Need to do some market research and see what is already out there that would be in cometition to the idea and get a feel for if it is something that would be wanted or not - and no, I'm still not telling you just exactly what it is.