Reddit mentions of Gas Turbine Theory (6th Edition)

I'm not sure if this is the book /u/IC_Pandemonium was referring to, but it might be:

The Jet Engine by Rolls-Royce

I haven't had a chance to read it yet but I have heard it is very helpful.

Some other suggestions:

Gas Turbine Theory by Saravanamuttoo

Elements of Gas Turbine Propulsion by Jack Mattingly

Jet Propulsion: A Simple Guide to the Aerodynamic and Thermodynamic Design and Performance of Jet Engines by N.A. Cumpsty
(I think this may be the book /u/IC_Pandemonium was referring to actually. The previous book I have not had a chance to go through but I believe it is supposed to be written very accessibly as well.)

Compressor Aerodynamics by Cumpsty

The Design of High-Efficiency Turbomachinery and Gas Turbines by D.G. Wilson

Hopefully one or a few of these help!

I would start with fundamentals

Hill and Peterson is pretty good for broad thermodynamics for propulsion systems:
https://www.amazon.com/Mechanics-Thermodynamics-Propulsion-Philip-Hill/dp/0201146592

Gas turbine theory is pretty good start for turbomachinery:
https://www.amazon.com/Gas-Turbine-Theory-H-I-H-Saravanamuttoo/dp/0132224372

You can build a turbopump without looking to power a rocket. (Pump water with steam or something) and in the endeavour I can guarantee you will learn so much.

If you mean turbine engines, Gas Turbine Theory by HIH Saravanamuttoo is an excellent text. I had the privilege of taking a course from the author during my undergrad and he is a walking repository of aircraft propulsion information. I believe he still delivers a lecture at Cranfeild once a year, I would definitely attend if you have the opportunity.

http://www.amazon.com/Gas-Turbine-Theory-6th-Edition/dp/0132224372

I don't think you'll have a problem as MechE. I suspect a knowledge of the complexities of full engine design wouldn't be necessary for OEM but if you want to know more Gas Turbine Theory is beautifully written and has everything you could want to know. If you can get it from your library I would definitely recommend it. I suggest an understanding of the relationships between total and static pressure/temperature before reading it though.

You are using the word theory wrong. If it means what you think it does, please explain the book Gas Turbine Theory. Do you believe we just have to "guess" at how they work?