a question/idea about gmail labels

is there any way that emails are send directly to a specific label instead of all dumped to inbox? say, is Sarah's email address is sorted in "work" category in my contact list, when Sarah sent me an email, it will be displayed under the "work" label by the gmail system.
I don't wanna bother using several email boxes for work, personal, blar blar..but feel comfortable sorting them under only one email box..i also heard from friend bothered by remembering all the account names and passwords of all the email boxes she have..