Learning c and making .dll files

Hello, I've read through previous threads and dont really see what I want to know there.

* Where is the best place to go to learn how to write a .dll file ?, I haven't done any coding for a few years and don't remember much of what I used to know.

* If I have a .c file and a .header file how do I go about making the .dll file ?

* What is the bare minimum I need to know to write .dll files ?

* What is a good program, hopefully free, to use to do all of the above?

* Is Bloodshed Dev-C++ Version 4 any good or even relevant to what I want to learn and do.


Thanks for any help.
Morac