I haven't used these notes yet (I forgot them I took them from my teacher in AS-Level), but these are apparently
very good notes for AS and A-Level studies.
A few reasons being that:
1) They are in slideshow format, so you can just play them out for revision purposes.
2) They're short and yet useful for quickly going through a chapter.
3) There are a few extras other than just powerpoint slides.

I studied from the same teacher in my O-Level/IGCSE, and though I didn't have a soft copy of his powerpoint notes, these ones he gave me.

Hope they help.