Advertisement is an easy way to reach lot of people. There are various sites and products available in market, who needs a place to keep their ads targeting people of their taste.
Grab the opportunity of earning the extra revenue by placing ads in your blogs. So, if you have the worry of how to get the ads, whom to contact, just wipe it off. Here I'm going to give you all the information you need.
Google - Adsense
To get ads from google, you need to submit an online application. They will review your application and inform you whether your application is accepted or rejected. If accepted, every step of how to place adv in your blog and all details will be provided to you. I'm still waiting for my approval. So cannot explain more. Hold on for few more days :)