A HelpPatch demonstrates the functionality of a node. Ideally a novice should quickly get an idea of what the node is about and an expert should get detailed information on its usage.
create a helppatch for a node by selecting it and pressing F1. if the node does not have a helppatch yet, a dummy patch with already the right name will open. simply press CTRLS to save the patch to disk and then start modifying it.
first find the most simple usage scenario of a node which will give the novice a quick overview
now explain the node a second time with a more advanced usage scenario and put that graph right next to the simple scenario
find further scenarios if applicable and place them right next to the existing
create IOBoxes for input pins that you set to values other than their default
don't label them (as if they were inputs) but write a comment next to them and explain their usage
in all your texts/comments please stick to the Conventions.NodeAndPinNaming.
create a see also section where you place related nodes that the user is supposed to also checkout.
add links to online information (wikipedia,..) regarding the functionality of the node
If you want your helppatch included with the next release please add them to this forum thread: missing-helppatches