If I start using adsesne this month, and google got some issues with it, may be invalid clicks, or regarding content, or whatever. So, when should I expect a warning mail from them ? IS that instant or there is some fixed period (monthly ?) that they let you know about their concern ?
Sometimes people get a warning and sometimes accounts are just disabled. Don't count on getting a warning. This is what you agree to in the terms of service: As long as you follow the Terms and Conditions and the Adsense Program Policies to the letter, you should be fine.