Online Update Issue!

Hi,

I was working on a desktop application basically it’s a product now the programming part is over and I have created MSI for this product.
So product and setup both parts are ready but now I have one issue with online updates for this product. I am planning to create a web service for online updates but I would like to know your thoughts as you guys are experienced.
I have used VisualStudio2008, language C# and setup and deployment project.
Please let me know, how to integrate it with setup and deployment project or with programming part or if any other right way for online updates.

Thanks