The thing is - besides it being a very long period - a lot of this was very personal. I'm currently reading a bunch of Henry I / Eleanor of Aquitaine material for an ongoing project, and the tutoring is mostly "We found someone and handed the kid over to them" - not a ton of documentation about what was involved, and the choices were mostly "fostering in a family connected with the child's family and politically allied." And it's *way* before any kind of formal accreditation for teaching (that's mostly a 19th century thing, though there's somewhat more formality once we start getting universities. Even then, though, a lot of that is a sort of *shrug, the university decide who is teaching for their own reasons*.

(This is also the period where you start getting formal grammar schools in England, but those are a whole different thing than tutoring, obviously.)

You're probably going to find the most info if you narrow down on specific individuals and see what you can find about them and their education/training. But it's also probably not going to get super detailed about things like specific works (For example, Thomas Ashbridge's The Greatest Knight (a biography of William Marshall) has a modest amount about William Marshall and education - both Marshall's own education, and him becoming Henry the Young King's mentor - but it doesn't get into things like specific texts or learning materials, because that just wasn't documented a lot of the time.)