socket programming for multi client

I am a nerd VB programmer having entered in to network programming with VB.I have just started to use sockets to create a chat application with winsock control.I would like to know the following details for creating a chat application with single server and multi clients:

1.What sort of coding should be done in server side?should I use single socket or use multi sockets ( 1 to listen and others to communicate)?If I use multi sockets
then what should be the port adress I should assign for each socket which is communicating with my clients?what should be the port adress of my listening socket.?
I have gone through karl's tutorials.I want to create multi client chat application.I require the coding in VB for the above case as Iam new to this type of application.I expect a sample application with coding which uses single server and multi client environment chatting.I
require both the server and client side coding in VB as I am first facing such a type of application.I am in urgency and I thank the person who will be able to give me the coding of the above mentioned application.

2.How to do the same above application using winsock.dll?Is is first of all possible to use winsock.dll?I have tried to use but my dll is not getting registered.What may be the probable reason for it?I require a sample application in VB which uses winsock.dll to create the above mentioned chat application.

3.How to use API calls to create the same application?What are the variable module level declarations I should make in order to create my single server and multi client environment?I would like to know the coding in VB both in client and server side for this chat application using API.I thank the person in helping me to solve my above mentioned application.

Any person with a solution along with coding can contact me at:

[email protected]