Hi,
I had been working on server side(c#) for a couple of years. But now I have been put on the UI stuff. I know ASP.NET in detail. But the landscape in UI stuff has changed dramatically from last 2 years. Everyone talks about jquery, json, asp .net ajax extender. I don't know how to cope up with this. Any thoughts on how I could come up to speed ?
The only advice I can give you is - take up each of the items you mentioned & go through the online documentation - something like jQuery & json are pretty useful & simple to grasp even though you might not cover 100% surface area.
My suggestion would be to get a solid foundation in Javascript/JSON first.
After that, move on to jQuery (a Javascript library to make your life infinitely easier).
Whatever time you have leftover, check out the ASP.NET AJAX Toolkit and how to develop/extend your own custom ASP.NET AJAX Controls.
Most of those new things (json,ajax,etc) come up with ASP.NET MVC.
jQuery: A wonderful javascript framework for dealing with the HTML DOM. Does great things for UI and AJAX. Now included with, and fully supported by, Visual Studio.
AJAX: Asynchronous Javascript And XHTML. Get/post data from a webpage without doing a full postback.
JSON: JavaScript Object Notation. Just another data format, less verbose than XML. Look into JSON.NET for more information.
Download the NerdDinner application for a good ASP.NET MVC sample. I'm not sure how much of the above technologies are used by NerdDinner, but it's a start.