What are the key on-page SEO elements I should focus on within Google Sites to improve indexing and ranking?

Focus on optimizing page titles and headings (H1, H2, H3) with relevant keywords. Ensure your main page title (the text that appears in the browser tab) accurately describes the page content and includes target keywords. Use descriptive, keyword-rich text in the body. For images, always add descriptive 'alt text' to help Google understand their content. Maintain a clear and logical content flow for users and search engines.