What user guide do you have?
there has not been an official pdf since version 7, as it seems, SketchUo prefered the online help system, reachable through [menu]Help in the desktop version of SketchUp. In SketchUp Free, the web based modeller, you can use the new search icon at the top of the left toolbar.
Some users have been busy creating a ‘classic’ Manual for the latest version:
There is no ‘best practise’ section, if you have no experience with the software, you might wanna play with it, before diving in.