anyway, first step would be to design the overall architecture, functionalities offered in different parts, and then communications issues. Which after you could go designing the client & server architectures. Anyway, as Kiran said, in client side (symbian phone) you need to use C++, or incase it would be sufficient, you could also look into the Java stuff.
then do the design first, find out what parts you are having difficulties and then ask more specific questions, you will notice that you'll get a lot better answers if you provide concreate problems.
Also have a look into SDK examples & documents, and also search information before asking. Quite often you can find good answers here, or by googling them, and locating answers by yourself can save a lot of time.
But ma expertise are in C#.net.....
i want technical help...i know the design issues
It is not a problem, since there are a lot of Windows Mobile devices (http://www.microsoft.com/windowsmobile/default.mspx), and you can develop in C# for them.
However this is a Symbian C++ forum, and Symbian is not Windows Mobile (they are competiting platforms in fact), and C++ is not C#, so it could be hard to help.
If you already have a Series 60 device, you may want to check:
- AppForge (www.appforge.com), claiming that you can develop in C# and Visual Basic (6/.Net) even for Symbian devices
- redFIVElabs (http://www.redfivelabs.com/), having a .Net CF 1.0 compatible runtime for Symbian, currently in beta stage.