I love this website and I can't recommend it highly enough.
Lawless French contains a huge array of different aspects of learning French and would be ideal for any students of French and even for teachers of French, too.
The categories on the site include:
expressions - this includes everyday expressions and idioms
grammar lessons - everything you could wish to know about all aspects of grammar: tenses, word order, adjectives, etc.. Ideal for student revision
listening practice - with scripts
reading practice - authentic texts - ideal for intermediate and higher classes
and every French teacher's best friend, the subjunctivisor.