A lot of moving around, placing and aiming can be done if you know simple vector math, rules for rotations/quaternions and can use some of the built-ins. Each problem is different -- this is hopefully enough theory that you can figure out most things, or understand someone else's vector/rotation code well enough to modify it.
This assumes you have a very basic knowledge of coding and know simple Unity3D navigation. Each section is only a few pages long.
Vectors and Rotations The whole thing as a pdf. 1/4th Meg. The links in the table of contents work.
Links to each chapter as htmls
Comments. There's also a post in the Unity Teaching&Learning Forum.
Jan 10, 2017: in Rotation chapter; rewrite the Quaternion sections , fixes and small grammar changes elsewhere.
Nov, 2018: re-edit entire thing. Redo first rotation chapter; added connect-cubes to misc examples. Added entire-pdf-with-TOC and html chapters (htlatex can do that. Who knew? Well, everyone except me.)