I've started a new (free online) book(let) titled:
Programming Bits, Bytes 'n' Blocks (in Ruby) Step-by-Step Book / Guide 
Let's start with the three types of strings, that is, bytes,
(string) buffers, and (frozen) strings, ...
Trivia Question: What's the difference between?
Happy bits & bytes slicing & dicing with ruby. Cheers. Prost.