This is a reference template:
On a project like this I usually make a Google Spreadsheet to keep track of the work to be done, something I started doing when I was editing a print magazine. Once all the pages to be created are in the spreadsheet I will add a formula to calculate what percentage complete the project is.
I am going to use the official Raspberry Pi colour palette, and then for further sites/courses I would anticipate using the colour palette associated with that particular platform – eg Arduino, Micro:Bit.
I am going to use CSS Variables for the browsers that support it to make adaptation easier.