You should join the youtube partner program and there is no trick if you upload quality video you will be able join partner program
You need to become elible and than after that you need to go off and sign up for the youtube partnership program. After that you can start putting ads on the video.
I recieved an email from Youtube Partnership after I totalled around 50,000 views on all my 4 videos combined. I recommend creating videos that are similar to other popular videos on youtube, for example, I play guitar, and my "How To..." guitar videos are the most popular videos on my profile, holding more than 70% of my total video views. Just to clarify with what yasar83 said about USA only, I am in the UK and I have Youtube Partnership. I believe it is for most countries. Good luck.
The first thing you should understand is that the ads which is relevant to the text describing every video is inserted automatically. If your content lacks specific description and/or contains an ambiguous title, the ad robot might not figure out the ads to display.
Yes. You need to have YouTube account. This will automatically create YT channel for you. Yes. You need to upload videos. No. YouTube ads are shown all over the world. Not just in the US.
You need to link your existing adsense account to the youtube account or you can apply for a adsense account from the youtube account itself. If you've got thousands of views to your original videos (or for the videos which you've got authorization from the copyright owner) then you can apply for a Youtube partner program (which will be giving you the additional benefits like customizing the channel logo etc).
There are more ways to monetize the traffic you get on youtube. You don't have to focus on YouTube partnership. You can try some other YouTube Monetization methods.