No prob. I have already used in several projects. Just look inside the publicTemplates.zip and you will notice that the files in there corresponds to the file structure you get after installing the template package. Just create a new .zip (name it just the way you like) and add files and folders. Add .dll's in the /bin folder and the files should be placed in the /bin folder of the web application. If you place one or more .episerverdata-file(s) in /util/install you will also get an option when browsing the site for the first time to install pagetypes and pages of your choice rather than the default publicTemplates. The CMS Manager even runs the installutil on the .dll in /bin - so if you want to run code when installing your assemblies thats the way to do it. I havent found any official EPiServer documentation on this, but it works :). It does however seem a bit buggy, you dont get any reference to the path or IIS site you are installing it to if you install the module after the initial setup, and I havent found a way to edit the web.config when installing.

Great! Where do I get the ZIP file? I've tried locating it without any luck :(

If you do a CMS Manager installation you will find it in C:\Program Files\EPiServer\Manager\Modules