Recommended websites and online platforms for UPSC preparation include Unacademy, Byju's, and The Hindu for current affairs. Platforms like Insights on India and Clear IAS provide valuable study materials, including mock tests and comprehensive notes. Additionally, sites like Telegram groups offer community support and shared resources. Utilizing these platforms helps candidates stay updated and access a range of study materials effectively. Engaging with online forums and discussion groups also enhances understanding through peer interaction, which can be critical for comprehensive preparation in a competitive environment.