VS 2010 [HELP] Creating a login system

Hello users, I come to ask a few questions about how i would go about making a login system for VB2010.

I have a forum where we offer almost 24/7 support ( i will not give out the name as it would be advertising) and basically i have hired people to be on during the certain times of the day. I want to go about making a login system for them to login to actually tell me that they are on and actively helping users.

I need to know how to go about making a login system but i need to be able to DISTRIBUTE it across the globe and then some. I want users to be able to login to the application, tell me what time they logged in and what time they logged out, Also i want to be able to add users to the application without having the previous users download the application again for the updates. Could i possibly make a program that connects to a certain file to my computer and just that one file alone and as soon as i add someones name and save it then that user can login with those details or would i have to go about it a different way.

Thank you and i will clarify anything and everything if someone is willing to point me in the right directions