in it s most basic form, Azure is just a highly available web-hosting environment - if you have an ASP.Net web application, you can deploy it to cloupapp.net and it should work.

To try it out, get yourself a Vista/7 machine, download the Azure SDK and VS Tools, and create a new Azure application. There are 2 main parts at this point, the Cloud project, and an ASP.Net Web Application. The ASP.Net will have a "web-role" relationship with the Cloud project. This is as it sounds, it is the visual front-end to the Cloud application, that interacts with visitors.

You can, at this point, just leave it there - it s a normal ASP.Net application with very good hosting. Your SQL connection strings should work, though you may want to consider SQL Azure. You can also host WCF services.

As Manoj points out, Azure does have a different programming model which you can take advantage to produce very robust applications. Azure also has the concept of Worker Roles, which are similar to Managed Services, in that they perform processing without a public interface. Instead, your web-roles take the requests, place them on the Queues, and the worker-roles then pick them up, process and send back responses.

It s a very powerful system, which I haven t fully explored, but the good news is that you don t have to be an immediate expert in the whole system, but can create simple ASP.Net sites as web-roles, deploy those then expand from there.

Have a go, it s well worth it

Toby

AppHarbor is a .NET Platform-as-a-Service. We can host your ASP.NET websites more or less un-modified and without the Visual Studio plugins and other crud that Windows Azure requires.

It depends on what type of cloud hosting are you looking for. There is some cloud hosting which will just give you space for application data like Amazon. While Azure gives you complete application framework which supports your application to be hosted in cloud. But programming in cloud is different programming paradigm than in traditional web form. You will have some limited classes from .Net framework available but better resources for scalability.

You cant directly use sql server in azure application. What you can use SqlAzure services.

Just referring a book which i feel would provide you the answer

Cloud Computing Book

EDIT :

Check this microsoft link Ramp Up

yes, it is supported and live demo of Asp.NET 4.5 Web Forms available on Microsoft azure websites... you can visit this link for detailed information Create and deploy a secure ASP.NET Web Forms app with Membership, OAuth, and SQL Database to Azure App Service