Recommended online resources for UPSC preparation include platforms like Unacademy, BYJU'S, and mylearningspace for video lectures and structured courses. Websites like Insights on India and ForumIAS provide valuable insights, study materials, and current affairs updates. Additionally, utilizing government websites, and newspapers supplements the preparation with authentic information. Candidates should also explore apps for daily quizzes and preparation tracking. Choosing a mix of these resources can cater to different learning preferences and enhance overall preparation.