1) Create a youtube account:-Very simple, if you have a gmail account then connect with the youtube with it. Youtube is a service of Google. I am not sure, but I think the account need to have atleast an age of 6 month for creating adsense account. You need to have atleast 18 years old for to get an adsense account.
2) Upload videos:-The videos that you uploaded in to the youtube need to be your own. Don't give background music if you create an album because it is against the copyright so create a video, give your own sound or not or capture a video using cell phone or camera. It is not necessary that it need to be a movie, even video less than 1 minute can also be uploaded to youtube but need to be your own. Your channel need to contain 3 or 4 videos atleast.
3) Join in youtube partner program-:Simply goto YouTube Partner Program . Now verify your channel and apply to adsense. You should have to wait for the adsense team to replay that you got approved adsense account. If you don't got it, don't worry keep try untill you get. If you got the adsense account then congratulation, you can now use your adsense account to get paid from your videos or you can use the ads in your blog and can generate cash with the traffic.
This is a very simple way which help to get adsense account. You will able to make some quick cash with the help of adsense. It is very easy to get some good number views for the video if you actively do social sharing and your video is search engine friendly. All the best.