There are two documents I consider reading:
Unix Signals Programming
http://users.actcom.co.il/~choo/lupg/tutorials/
Beej's Guide to Unix Interprocess Communication
http://www.ecst.csuchico.edu/~beej/guide/ipc/
Also, have a look at the manpage:
http://www.mcsr.olemiss.edu/cgi-bin/man-cgi?signal+5