In this article, you will find the following interesting gist on the important reasons why Google disabled people's accounts and if you have been banned by them before, you may need to know why so you can guide yourself next time.
Google rarely bans adsense accounts without tangible reasons, if you want to know how to avoid getting your adsense account banned you
need to play by the rules of the game.

Placing Adverts on Incentives Webpages: Placing ads on websites that encourage people to click in order to give them incentives like paid to click(ptc) and paid to read mails(ptr) websites. Placing your links would be at a great risk of getting your adsense account banned!

Violating Copyright Materials: In no way should you display Google ads on web pages with content protected by copyright law unless you have the necessary legal rights. Always write your own content!

Encouraging People to Click Ads: Never directly encourage your visitors to click your adverts displayed on your webpages. Invalid click activities could get your adsense account out the door.

Posting Prohibited Contents: Adult materials, gambling contents are some of the prohibited niches/contents that Google frowns at. In addition, do not write contents related to weapons or ammunition (e.g. firearms, firearm components, fighting knives, stun guns), Gambling, Casino, Pornography, Adult or Mature, Alcohol, Tobacco, Racial, Hacking, any other content that is illegal, promotes illegal activity.

Altering the adsense code: Doing this will out-rightly place a ban on your account. But why would you alter the ads in anyway. You are only permitted to adjust the colours, fonts, shapes all made form your adsense account interface.

Nice and Interesting money making posts here: http://www.wazobiablog.com/2011/12/5-reasons-why-your-adsense-account-was.html

Nice one here and I'm sure that you are on bloggerslab

Yes I am there!