Use WCF webservices !
Build a web project using wcf!
To test it on local, host it in IIS
when it is done, go in your client side, add serviceReferences, enter the url of the service (it should looks like http://localhost/..../myservice.svc) and it will build the proxy class.
In your code, use it like this
using(MyServiceClient service = new MyServiceClient() )
And when your server is deployed on internet, use the same pattern with the new url!
In your web.config, change to this
<servicedebug includeexceptiondetailinfaults="false" />
<directorybrowse enabled="false" />
so your work won't be use by someone else !
using(MyDebugServiceClient service = new MyDebugServiceClient () )
using(MyProdServiceClient service = new MyProdServiceClient () )
if your server has an entity model, don't use wcf sevices, but use wcf dataservices.