Enable shaper and ensure all the default worlds are installed. Run the installer as Administrator to ensure that you can edit the settings and create files. If you don't do so Windows will treat worlds and it's files as if they belong to another user and will not let you edit them.
Jimbly provides the software and excellent instructions here.
One of his worlds, by design, has a series of 49 rooms called the Gauntlet. As you pass through the Gauntlet it will prompt you to download worlds that you do not already have and ask you if you want to reboot, as well. Click yes to confirm the downloads and no to the reboot option until you have passed the entire Gauntlet and you will have all of the worlds when you exit. This step is significant in that many users build their worlds by linking to the textures and objects from these default worlds. Without them you will see bright solid colored walls where these textures are linked and objects will not appear at all.
The Guantlet's location is:
http://www.ittraining.net/jimbly/groundzero.world
Once you have a complete set of worlds and the tools enabled to edit and create, worlds provides a set of assets to practice and learn with.
Download some basic files.
The tutorial explains the process of building with shaper.
It explains creating rooms, connecting them with portals, adding objects and textures.
