Una explicación con audio

http://www.curso-ingles.com/gramatica-inglesa/few.php

Una explicación con muchos ejemplos y audio

http://www.shertonenglish.com/resources/es/adjectives/adjectives-quantitative.php

Y en esta un montón de ejercicios

http://www.agendaweb.org/grammar/quantifiers-quantity-exercises.html

Uncountable nouns
Countable nous
Other
HOW MUCH water do you drink? HOW MANY people were there?

A LITTLE (and that's OK, I don't need more)  		A FEW (and that was enough)

I drink LITTLE water (not enough, I think I should drink more) There were FEW people (not enough, e.g. the party was boring)

I drink ENOUGH water (sufficient) There were ENOUGH people (sufficient, just the right number) I'm tall ENOUGH to play basketball
I don't drink MUCH water (negative sentence) There weren't MANY people (negative sentence)

I drink A LOT OF water There were A LOT OF people He eats A LOT.
I drink TOO MUCH water (more than necessary) There were TOO MANY people (more than necessary) I'm TOO tired I'm going to bed.