PR several books a day- if you don't care to activate a book, still PR it just so you can activate it any time in the future - if for no other reason.
done all at once, or did anyone read those many books spread out through out the day.-
Related books can be done back to back but if you want to go from one kind of book to another you should take a break, get out of state and then get back into state with your new purpose and affirms etc for the new book. Personally doing 2 PR sessions a day is plenty- beginning and end of the day. That gives plenty of time for incubation. Once the novelty of waiting for Spontaneous Acts wears off you'll probably PR at night and activate during the day and leave it at that. To me that seems to save the most time and gives the best results because there's a dream session in there b/t PR and activation.