There isn't actually a dedicated cheat sheet for a HTML simple adder, but the actions are exactly the same as for the Swing Simple Adder. There is a SimpleAdder HTML installed with Jubula, so you can try out the same test on that. The main difference between HTML and other toolkits is that you perform the mapping via click.
Bear in mind as well that the plugin (e.g. in Eclipse for Testers) doesn't contain the necessary code to execute HTML tests / start HTML AUTs. You will have to use the standalone to run HTML tests.
If this information doesn't help, then let us know where you're getting stuck.