Richard,
It's an interesting experience to compare the sample spectra from Richard Walker's excellent Spectra Atlas (
http://www.ursusmajor.ch/astrospektr...age/index.html ) - down the bottom rhs.
with the detailed spectra in Gray&Corbally....
The next step up the learning curve is the challenging:
"The Observation and Analysis of Stellar Photospheres" by David F Gray.
This covers the modelling aspects of stellar atmospheres and the impact/ effects of temperature, velocities, chemical composition etc. etc.
Onwards and Upwards.