the Journal of Cell Biology has a website to access a vast database of perfect slides
http://jcb-dataviewer.rupress.org/
As a teacher of biology for many years I am delighted that your son has decided to take the subject. If he is 'good' at English and has the capacity to memorise and retain specific information and has the capacity to convey these concisely in written form then he should find the subject straight forward
denis o sullivan
http://www.5min.com/Video/An-Introduction-to-Biology-150605658
Unit One: Biology - The Study of Life
Unit Two: The Cell
Unit Three: The Organism
http://www.5min.com/Video/Respiration-An-Overview-150625725
http://www.open2.net/treeoflife/index.html
for germination and all things plant .....