
The Following are the Arduino tutorials and resources for learning Arduino at various levels.
Paul McWhorter New Arduino Lessons – A Tutorial for Everyone
This Great Arduino Tutorial by Paul McWhorter is recommended for everyone as the tutorial teaches you the basics and then takes on the complex theory, making you an expert.
You can also check out his Old Arduino Tutorials.
Arduino Tutorials – Beginners
1. A Beginner’s Guide to Arduino by tttapa – Instructables

This Tutorial by tttapa explains you the basics of Arduino and enables you to think more of the working of the various ICs on the Arduino Board. It also gives you a very detailed and understandable explanation about Arduino.
Look at the Article - Here
2. Arduino For Beginners – Makerspacesdotcom


This fantastic tutorial for Arduino teaches you the basics as an Absolute Beginner and then leaves you as an Arduino Enthusiast.
Look at the Article - Here
3. Arduino Basics 101 – GreatScott!
Arduino Tutorials – Intermediate to Experts
1. The Arduino Forum

This is a great platform for Troubleshooting and creating new projects. You can also look at various sources at the forum for learning more about each sensor.
Many people also post their problems working with a sensor and how they solved the problem.
Look at the Forum – Here
2. Learn Arduino – Adafruit Learning System

Learn about Arduino, Sensors and Modules from the founders at Adafruit.
Look at the Article – Here
3. Arduino Projects – Mert Arduino
Explore the various projects from Mert Arduino. Schematics and Code are also provided so that you can try to tinker various projects from the channel.
Check out the Channel – Here
4. Arduino Projects – Electronoobs
5. Arduino Projects – How to Mechatronics.com
Check out the Channel – Here
Check out the Channel – Here