737 Lessons - help

Hi guysHaving been flying ga aircraft for some time now, i thought it about time i started flying something a bit bigger. I've attempted the 737 lessons but have found them rather lacking in background information regarding the fundermentals of flying a 737. Can any of you guys point me to a site where i may find this information.Also, when i attempted to load a 737 lesson, i received an "aircraft initialisation failure - boeing 737-400" message. The lesson continued to load, although i could only use a 737 is that was the last aircraft type that was flown. Could this be related to the fact that i changed the 3 default paint schemes some time ago (for ai purposes) and no longer use the names "Paint1" etc within the aircraft.cfg file ???Thanks for any assistanceGary