Some helpful online resources for UPSC preparation include platforms like Clear IAS, Unacademy, and BYJU's. These websites offer extensive study materials, video lectures, and quizzes tailored to the UPSC syllabus. Additionally, forums like Insights on India's and ForumIAS provide community support and peer interactions. Social media groups on Facebook and Telegram are also valuable for sharing resources and motivation. Utilizing these resources efficiently can enhance understanding and retention of crucial topics, thereby optimizing preparation efforts.