Input via the serial port for a C program

Hello
I am doing a electronics cource at the moment and have done some C++ programming but not alot, what I need to know is whats requried for a C program to read data from the serial port, I know about reading data from a file.

The reason I ask is because I would like to send data from a 8051 to the com port and have a C program read and store the data.

Any information or links would be helpful.
Thanks Anthony

I've just done a board search
"serial port" Showing results 1 to 25 of 207
Which of those is confusing you?

Oh, and next time mention your OS and compiler.

Windows Xp
microsoft Visual C++ 4.0

I did a search and using "serial port" and your right there is a heap of information.
I'll start reading