Sell Ads on my website

We need someone who can sell ads on our website. We need someone who knows how start ups can sell ads on their websites. We need someone who knows more than typical adsense model. We wish to sell ad spaces on our blog and on our website. Please let us know if you have relevant experience with the same. We wish to monetize our website and blog with minimum payout period. The job is to ensure we predict correct CPM revenues. Do let us know if you can handle this.