You could just read this and it basically gives you everything you need and an example to boot...
/help on text
But, here:
on *:text:*help*:#: {
msg $chan Someone typed help.
}
Note that you can remove one or both *'s around "help" if you don't want to respond when help is anywhere in the line. If you only want to respond when help is written by itself, remove both *'s. If you want to only respond if it's the first thing on the line, just remove the last *. Leave both if you want to respond no matter where it is written in a line of text.
