Google has provided specific quality guidelines in its Webmaster Guidelines. These guidelines help your website get crawled and indexed.
- Do not use hidden text or link.
- Avoid cloaking or sneaky redirects.
- Do not send automated queries to Google.
- Not to load pages with irrelevant keywords.
- Avoid duplicate content.
- Do not create pages with malicious programs
- No doorway pages to cheat search bots.
- Provide a value/reason for your customers to visit your site if your site uses affiliate program.