R help - May 2010 - analysing categorical explanatory variable effects

Good day R -users,

I've a general question, I have a quantitative dependant variable and
categorical explanatory variables my aim is to identify  the most
significant variables  that explain my dependant variable behavior,

I know  this isn't the right forum for a such question but any helps
would be highly appreciated,

Thanks a lot in advance,
Ama.