Two fairly extensive lists, which I found by googling for “french idioms”:

http://french.about.com/library/express/blexdico-a.htm
http://www.languagerealm.com/french/frenchidioms.php

Here are a few links to pages with commonly used french phrases:

• this one is from Larousse.fr (dictionnary maker) and has various categories for commonly used phrases.
  http://www.larousse.fr/dictionnaires/guide/anglais/
• this link shows common french idioms, with explanations and the origins of the idiom.
  http://lewebpedagogique.com/culturefrancaisepourtous/vie-quotidienne/les-expressions-courantes/

To address “a l’egard de”, it has similar meaning as “en rapport a”, “a propos de”, “en ce qui concerne…”

A l’egard de ta voiture… -> Regarding your car…

“A l’égard de celui qui vous prend votre femme, il n’est de pire vengeance que de la lui laisser.” -Sacha Guitry
“With respect to the man who steals your wife, there is no better revenge than to let him have her”

I hope this helps.