MakeCode Micro:bit Programming Application: https://makecode.microbit.org/
Micro:bit Classroom Application: https://classroom.microbit.org/
Google Teachable Machine: https://teachablemachine.withgoogle.com/
Connecting to External Power Supply Over 3V (scroll down page)
The external battery pack supplies a higher voltage than the micro:bit. Do not connect the positive (+/red) wire from an external battery pack to the micro:bit as you will damage it.
Troubleshooting:
Always test your code in the browser before downloading to your Microbit. This is especially important when you have connected electronics to your board. If it works in the browser but not on the board, then you likely have an issue with your electronic connections.
Thermometer: https://microbit.org/projects/make-it-code-it/thermometer/
Min-Max Thermometer: https://microbit.org/projects/make-it-code-it/max-min-thermometer/
Celsius to Fahrenheit Conversion: https://microbit.org/projects/make-it-code-it/fahrenheit-thermometer/
Soil Moisture: https://makecode.microbit.org/projects/soil-moisture
Plant Watering: https://makecode.microbit.org/projects/plant-watering
Make AI Robots: https://makeairobots.com/ (Companion Book HERE with LOTS of project ideas!!)
Websites with Project Ideas
Adafruit Learn: https://learn.adafruit.com/search?q=microbit
Micro:bit Foundation: https://microbit.org/projects/make-it-code-it/
Hackster.io: https://www.hackster.io/microbit/projects
Instructables: http://instructables.com/teachers/microbit/projects/
Books
Micro:bit for Mad Scientists: 30 Clever Coding and Electronics Projects for Kids
Make: AI Robots: Create Amazing Robots with Artificial Intelligence Using micro:bit
Some Fun Accessories
Adafruit, Elecfreaks, and Amazon sell various kits, accessories, etc. Here are a few we have tried: