To begin delving into Three.js, it is important to have a solid foundation in JavaScript. One recommended starting point is W3schools.com, an educational platform created by a reputable Norwegian software development and consulting company. This website offers a comprehensive JavaScript course that covers essential topics such as DOM manipulation, building interactive websites, and other fundamental concepts. Once you have grasped the basics of JavaScript, I suggest visiting the official Three.js website at https://threejs.org/ and exploring their documentation section for further learning.