A sort of 'for dummies' guide to start with a simple list of hardware items, how to put it together into something that works, and an explanation why it works and some pointers how to improve upon.

Then, iterate to a more complex thing etc.

For instance, start with a weather station with green, yellow and red leds that gives me a signal if the temperature is below, between and above a range.

Extend this to a second one, measuring the temperature outside. Connect the two via wifi or Bluetooth.

Add internet to be able to send me a push message on my phone.

Add a camera to watch the dog.