Hi! The others on this thread have answered your questions fairly well but I found this book to be really helpful for getting my head around learning Gaussian and also if you use the GUI or decide to look at the output files in a text editor.
https://www.amazon.co.uk/Exploring-Chemistry-Electronic-Structure-Methods/dp/0963676938
There tends to be second editions pdfs floating around on the internet but I haven’t come across any 3rd editions. Hope this helps!
Computer Simulations of Liquids by Allen and Tildesley is good https://www.amazon.com/gp/aw/d/0198803206/ref=dp_ob_neva_mobile
Frenkel and Smit Understanding Molecular Simulation is also great, but I don’t recommend it for a beginner https://www.amazon.com/Understanding-Molecular-Simulation-Applications-Computational/dp/0122673514
Perhaps this?:
Modern Quantum Chemistry: Introduction to Advanced Electronic Structure Theory
Attila Szabo and Neil S. Ostlund
There’s a really good one published by Wiley called Essentials of Computational Chemistry. I work in a comp chem lab and this book is still extremely relevant and serves as a great reference imo. If you really really want to get into the theory of MD check out this set of lecture notes. http://fy.chalmers.se/~tfsgw/CompPhys/lectures/MD_LectureNotes_181111.pdf https://www.amazon.com/Essentials-Computational-Chemistry-Theories-Models/dp/0470091827
You want TOTAL ENERGY = -343.0665513865
. Everything else is a contribution to that number.
You might also be interested in this book.
I don't know anything about the book you've linked to (though I probably should), but this one always seems to pop up. Again, no experience with it...