Please don't get carried away - there is much more material on this topic than you can possibly use.
There are numerous texts for pilot training which explain their use - just search on Amazon for them (then borrow them from the library). The material for private pilots is usually simpler than that for professional pilots.
The industry standard data sheets on the aerodynamic effects of slats and flaps are those published in the UK by "ESDU", the Engineering Sciences Data Unit. To obtain those, you're likely to either have to pay, or to get them through your local university library - if that university offers engineering anyhow.
There are several good aircraft design textbooks which will cover the topic; I suggest as (relatively) easy using Darrol Stinton's "Design of the Aeroplane", which is widely available and very well written.
A lot of historical technical material can be downloaded for free from the
NACA reports server -
here's one to get you started..
Very best of luck,
G