Some one says, H1 Tag is very imp in SEO, while someone says PPC can improve keyword ranking on organic SERP. Don’t confuse, here are top 10 SEO Myth:

Want to know more about SEO Myth, here is the secret of SEO Myth1. You should submit your URLs to search engines.
2. H1, H2 etc must be used for high rankings.
3. The more times you repeat the keyword in the page, the higher it will rank
4. PPC ads will help/hurt rankings.
5. Your site will be banned if you ignore Google’s guidelines.
6. Your site will be banned if you buy links.
7. PPC is better than SEO
8. Words in your meta keyword tag have to be used on the page.
9. SEO copy must be 250 words in length.
10. You need to optimize for the long tail.