I've heard of figure painting methods being described as such. Can anyone elaborate on this? Are there books or tutorials teaching this method?
As pointed out, its a term to denote a time for a modeler when things were done differently. It would be different for each modeler depending on their age. Old school to some people would be Renwal and Aurora kits, maybe balsa wood models, and tube glue. For others, its 1989 DML kits, Testors paint in a bottle and vacuum formed accessories. I look at figure painting old school as a time before acrylics were used extensively, and enamels were the preferred paint. Some look at oils as old school, anything but acrylics being considered a bit old fashioned. I don't know what came before Verlindens tutorial on figure painting, but its how I learned, and is now REALLY old school.
Speaking of old school, back when I was learning model building by experimenting and not asking everything on the Internet (didn't exist in the early 80's), I frequently would "mess up" my paint jobs with a poorly done wash that would stain the underlying base coats a different color. I learned over time to do a wash more precisely (now referred to as a "pin wash", I think), or only over a clear coat. 30 years after these "mistakes", a wash used to change the base coat color became a new fangled technique called a "filter" that everyone seems to think was something new and great and can't be done without. Back in the day (another term like old school) it was nothing but a messed up wash. Who knew???