well, before applying to adbrite, please check that:

you have a good blog/site

with traffic

its popular

then, if you have all of this, you can use adbrite.

first: what is adbrite?

adbrite is the intermediary between advertisers and you. sign up at this page:

then, make an ad. be sure to place it at the top of your site, or in a relevant place. now wait, and in some weeks, maybe some advertiser purchases an ad. while then, they will place ads related to your site, and you will get little money from this. so adbrite is only recommended to big sites.