I'm new to Programming, and I honestly have no idea how I am to go about coding my program, so I'm looking for some help; someone who can help me with code and explain exactly what is going on.

Here's the run down of my program, it helps if you view the screenshot too:
http://img24.imageshack.us/i/tfcalc.jpg/

Basically, the user selects a name from the dropdown menu, then in the first input box, "Last Killed", they place a date and time, in the format displayed in the text box.

When the Generate button is clicked, a beginning time and ending time are displayed in their appropriate boxes.

For example:
I select "Visual Basic Nub" from the dropdown (we'll pretend it's on the list) and input 01-20-2010 10:30 AM.
When I click Generate, the program knows that because "Visual Basic Nub" has been selected, it at firsts adds 1 day--then for the "Begin" time, it subtracts 6 hours from 1 day, or 24 hours, and the "End" time, it adds 6 hours to the 1 day, or 24 hours. So, my time frame would be:
01-21-2010 04:30 AM -- 01-21-2010 04:30 PM

Hopefully this makes sense and is easy to do.
Any feedback is appreciated!!
Thanks very much!