Barannfin,
if you want to do some more reading, "The Helicopter Pilot's Manual Vol 2 - Powerplants, Instruments and Hydraulics" by Norman Bailey has a good introduction to gas turbines. It takes the Allison 250 series turboshaft engine (pretty standard helicopter fare, I believe) and goes through the processes and components at an easy to understand level. It's backed-up by plenty of schematics and gives an introduction to concepts such as compressor stall and surging.
The book is a little pricey for it's contents at 33 Euro (subjective

) but you might be able to borrow it off someone. I'd loan you mine but I suspect we're in different hemispheres!
Seeya!
Irlandés