You can submit multiple videos for monetization simultaneously. Here's how:
Select videos in your Video Manager. (You may submit up to 100 videos for monetization at one time.)
On the Actions menu above your videos, click Monetize.
Confirm or change the ad formats you want to enable for these videos, and specify your videos contain paid product placement.
Your video will go through a standard review process before ads begin to appear. You may be asked to submit information proving you own all necessary commercial use rights to any or all content in your video.