The following video is a good starting point to familiarize yourself on how to use key shortcuts and interface. It also covers the preparation of unit system to millimeters and adjusting grounding plane grid size for 3D printing. All shortcuts are available at the following post.

Much better project and recent one, covering 3D print process in Blender.

Use the following Blender template for setting the 3D environment for your project. Adjust the printing area according to your volume size.

The following video presents setting print area, start blender with printer template.

Other Tutorials

youtube 3D print city scapes via Blender.