I need to know what is rich snippets and its effect on SEO?
All the information that is shown in a search page item under its Titl, URL, description is the "rich snippets". You are determine their structure with different ways in your page code. You can find many usefull reading in these links:
Some one know about wordpress plugin for rich snippets I have tried several but it does not seem to be working for me
Well, it looks like most of the part has already been covered by @tdrosiadis and to understand what rich snippets is? I think I can came up with little defnition- It's about providing search engines an additional information about your website, so it can display more useful information to people searching.
Rest of the things are Ditto as @tdrosiadis !
@tdrosiadis and @kelly burby thanks to giving me this useful information.
Thanks a lot! Feel nice to help out. You can consider giving a solved flag to my answer also if you feel like :)