People:
Here's some practice. Hand in the exercises if there are no answers available. xxxx
http://www.easyenglish.com/lesson.asp?much.txt
http://esl.about.com/library/beginner/blmuchmany.htm
http://www.1-language.com/englishcourse/unit9_dialogues_exs.htm
http://www.geocities.com/ericsquire/grammar/countbl3.htm
http://iesitaza.educa.aragon.es/DAPARTAM/ingles/cursos/3_eso/Exerc_3_eso/Grammar/countable.pdf

Theory
http://www.learn-english-online.org/Lesson37/Lesson37.htm