I am new to orkut application development. I just came to know about jQuery and found it very interesting and useful. Is it possible to use jQuery with open-social to develop orkut applications? Please give me a link to some examples too.
Did you try Google?
Yes, it is very much possible to use jQuery with Orkut's APIs. The Open Social framework allows you to log-in, create a session, access the user's data (with some restrictions) and so on. jQuery on the other hand provides a set of generic APIs for a HTML document handling. You may want to read the tutorials separately as also this 'Using jQuery with other libraries'.
You may want to take a look at opensocial-jquery.