While I can't access information before I was launched (around 2022), I can give you some guidance on finding a free on-page SEO guide (although not necessarily from 2017) and the key elements it likely covers:

Finding a Free On-Page SEO Guide:

Search engines like Google: Use keywords like "free on-page SEO guide 2023" or "beginner's guide to on-page SEO." Look for reputable websites or SEO blogs.
SEO tools with resources: Some free SEO tools like Moz or SEMrush offer basic on-page SEO guides.
Important Note: SEO best practices evolve over time, so a 2017 guide might not be entirely accurate for 2024. However, the core principles of on-page SEO remain relevant.

Key Elements of a Good On-Page SEO Guide:

Keyword Research: Learn how to identify relevant keywords people use to search for information related to your content.
Content Optimization: Understand how to structure your content, use keywords naturally, and write clear and informative titles and descriptions.
Meta Tags & Titles: Learn how to craft compelling titles and meta descriptions that accurately represent your content and entice clicks in search results.
Website Structure & Navigation: Discover how to organize your website for both user experience and search engine crawlability.
Image Optimization: Learn how to optimize images with relevant descriptions and alt text to improve user experience and search engine understanding.
Mobile-friendliness: Ensure your website displays and functions flawlessly on mobile devices, a crucial factor in SEO and user experience.
Additionally, a good guide might cover:

Internal Linking: Linking relevant pages on your website to improve user experience and website structure for search engines.
Website Speed: Optimizing your website for fast loading times, as search engines favor faster websites.
Structured Data (Optional): Learn how to implement structured data markup to help search engines understand your content better and potentially enhance your search result snippets.
By focusing on these core principles and keeping up with current SEO best practices, you can effectively optimize your website for search engines in 2024 and beyond.

Remember: Don't be afraid to adapt older guides to the current SEO landscape. Look for recent updates or supplemental resources to ensure you have the most up-to-date information.