I highly recommend the following two books to study Logic from the beginning (for a layman);
Logic: An Introduction to Elementary Logic by Wilfrid Hodges.
Introduction to Logic: and to the Methodology of Deductive Sciences by Alfred Tarski.
Also i highly recommend everybody to read the great logician Alfred Tarski's classic book Introduction to Logic: And to the Methodology of Deductive Sciences to really understand "Logic" which is what Formal Reasoning is based on.
In logic, "Introduction to Logic: and to the Methodology of Deductive Sciences" - Tarski.
I wish that I started studying these three books before college, in order: 1) Tarski's 2) Strang's 3) Jaynes'