I think you've made a really good start with the guide.

One thing to remember when you write technical documentation is that people have a diverse amount of knowledge so you have to assume they know nothing and every time you introduce a new concept, term or acronym then consider adding it to a glossary. An example of this would be the different types of connectors discussed.

Also if I was starting a club from scratch I would find it really useful to have a bill of materials to accomplish a specific task and example components to use e.g. removable link, fuse and power light

Hope this helps
S.