SMS Sending service

I want to develop a website which provides the facility of sending free sms to any mobile. the technology which i want to use is with c#.

How should i move further? I need ur suggestions.

Well, it is easy to send SMSes with C#. All you need is a SMS gateway provider. They should have a webservice or something that you can use and they should also have all the documentation. Just know, that you will have to pay for the SMSs sent. But it will be less than the original cost of a sms. Depending on the country you are in.