Laptop Schematic Diagram

What products / software should I get for taking notes in a classroom?

I’m a 2nd year Computer Engineering student, and my handwriting sucks, but I type 90 wpm!
So I realized that typing could be much easier.

But the issue remains that I get alot of graphs and diagrams in a lecture (circuits, Schematics, …)
I thought of getting a tablet to go with my laptop.

What kind and what size should I get? And is there any software (preferably free) that makes it much simpler to get all the notes and symbols and diagrams fitted together easily?

Thanks!

The tablet is an excellent idea. As for the software, my students just use whatever word processing they have – and I think mostly .rtf.

laptop Schematic Diagram