How to read and write a 24-bit bitmap file

I need to read and write a bitmap file and am unsure on how to begin this...

I have the way i want the read and write functions to work but am not sure as to what header information and such i need to pass to get this to work.
Here is the read function that i need to code:

/*Read Bitmap File function
  Function: readBMPFile(outfile, bmpHeaderRef)
  Purpose:      gets the bitmap from the infile
  Params:      infile - bitmap file of image
                  bmpHeaderRef - a reference to the memory buffer
                  for the header information
  Return:      reference to a memory buffer containing the bitmap
                  data, NULL if unsuccessful reading the image file
  Algorithm:
*/
BYTE * readBMPFile(FILE *inFile,BMPHEADER *bmpHdrPtr)
{
      //Insert code
}


and here is the Write bitmap code that i need to work with
/*write Bitmap to File function
  Function: writeBMPFile(outfile, bmpHeaderRef, bmpDataRef)
  Purpose:      writes the bitmap in memory to the outfile
  Params:      outfile - bitmap file of write image to
                  bmpHeaderRef - a reference to the memory buffer
                  for the header information
                  bmpDataRef - a reference to the memory buffer with
                  the bitmap image data
  Return:      boolean indicating success or failure of write
  Algorithm:
*/
int writeBMPFile(FILE *inFile,BMPHEADER *bmpHdrPtr, BYTE* bmpDataRef)
{
      //Insert code
}


Hopefully someone has a simple solution and could explain there code well enough because i'm a beginner c programmer.

Thanks in Advance.