We all know that Google has certain rules and regulations when it comes to hosting and maintaining your own web site. However, sometimes we are too busy with making our web site look good and effective and we never really know that accidentally we have violated some policy of Google which is when Google penalizes us for our wrongdoings and we realize where we have gone wrong. Many of the web site owners say that they all have made some or the other mistakes for which they were penalized by Google so avoiding Google penalty is really a tough task but we can still avoid Google penalty.
Some of the reasons that would lead to Google penalty is spamming or having hidden content in your website. Google can also penalize you for over optimization of your web site which might sound awkward to you but it actually makes sense when you understand the basics of SEO. Some of the web sites which are purely information-based often get penalized by Google for over-stuffing the keywords. This normally happens when the articles or the web site information is written by some non-professional writer who has no idea about how much percentage of keywords are enough for a site.
Once you are aware of the reasons, you can make sure that you are not doing any of such things through your web site which would force Google to penalize you. You can also read Google guidelines that clearly explain more about the things that you should not do through your web site. If you are not really sure you can find some forums and discussion sites where web site owners and new entrepreneurs discuss more about such topics in order to avoid Google penalties and from getting their site affected seriously.