Sharepoint 2003 Help required

[neongod]

I have just started working on sharepoint v 2.0. In my site i have a list. I need to customize it. I mean when the user clicks new the fields should be populated with previous values in the list.

I am using sharepoint 2003. How to start on. Do i have to use Visual Studio 2005. do i have to install any plugins.



Please help me. I know my question are very naive.



Thanks