12/3/2014 7:12 PM
The University of Georgia has a self-study class which qualifies for GCSAA points - "The Principles of Turfgrass Management". It is listed on the Distance Education section of this website. It covers the topics you mentioned. It is sort of an introduction to the topics. 1 chapter on soil, irrigation, insects, weeds, pesticides etc... vs. a semester long class in each subject you took in school.
Youtube has a lot of videos. You could buy the class and make copies of the "book". (It comes in a 4 inch binder and has about 1000 pages)
Have your crew read a chapter for homework during the week, watch a related video and then talk about it.