Is there a Tutorial on implementing mib2c stubs?

Hey,
 
1) How do I decide which mib2c to use?
  [I got to learn them all and see which one fits.
   Is there a tutorial for this, or should I run each of them and read
the code comments?]
 
2) Is there a tutorial explaining how exactly the Agent handler
mechanism works?
 
Thanks,
Erez.