I found that many people don’t know how to deal with Google when problems happen. Here list of forms to report common problems to Google.

• Adsence policy violation- use this form if you find websites which violate AdSense policy using spam, fraud clicks, inappropriate ads, illegal content, hints and tricks to increase click rate, offer to exchange clicks etc.
• Contact Google - form to give feedback or report a problem.
• Removal requests - requests to remove content, pages, or website.
• Report paid link - to make complaint you should be logged in to your Google Webmasters account.
• Remove inappropriate page from Google search - you should be logged in.
• Report copyright issues to Google and YouTube - if someone stole your content, idea, material you should use this form.
• Report copyright infringement of the image - you should write official letter to Google office.
• Report spam in search results - spam, cloaking, hidden text, “black hat” SEO, inappropriate content, and other issues to improve search results.
• Share success - to give feedback or to share your success you can use this form.
• Report offensive content - make sure to report all types of illegal content.
• Post question to Google Help Group - post question or comment about Google Web Search.
• Contact form for bloggers - post your question, feedback, or complaint about Google Blog search or other blogging issues. 
• Report security issue - report websites which harm your computer, steal information, send viruses, and other issues.

Picture source: http://www.techwithoutwires.com/50226711/a_google_wiki.php