When an app appears, pull down the notification shade and long press on that item. A button will pop up labelled "App info." Tap that button, and it will take you to the app that's generating the ads. Uninstall that app.
Also you can download an app called "airpush detector" open it and scan your device it will give you a list of applications that generate these airpush adds you can then just select the offending applications and uninstall or you may Choose to keep the app. I have had a couple apps that I kept and chose to just live with the ads as I liked the apps