when to trim the leaves???

hello all!!!!
this is all new to me , when do you start to trim the the leaves on the plant?? i hear people say trim all the bottom waterleaves and some say leave it alone, so i'm kinda confused!!! any suggestiion would be appriciated!! or link to thread that explain more would be cool too!!:thumbsup::thumbsup::thumbsup:
btw my plants are out door:wtf:

Trim the leaves after you cut it down. Before that, leave them alone.

I just take off any leaves that are turning yellow. Nasty little leaf sucking buggers are often attracted to yellow leaves.