These notes started as something just for me, quick visual reminders of what a certain node was, how a certain trick I used to do in Maya would be done in Houdini, other little tricks I picked up from co-workers when first learning Houdini. It became a handy reference for friends who were also starting out in Houdini, and I was pleased to find a lot of other people have found it useful too.
A key thing with all these tips is to keep them short and to the point. Other people are great at making long in depth video tutorials, I just don't have the time! I've tried to reduce all these examples to the bare minimum to achieve a certain effect, a gif to show what it does, and some accompanying text. If you're confident in another 3d app, and are looking for a quick intro to Houdini, this is a good way to get started.