These links will help all web developer and who all works in the web.

1. PHP 5 Online Cheat Sheet v1.3
2. PHP cheat sheet version 1
3. List of all the documented PHP functions
4. PHP Functions to Work With MySQL
5. PHP Application Security Checklist
6. Handy Cheat-Sheet of MySQL Commands
7. Download MySQL cheat sheet-v1
8. HTML Colors Cheat Sheet
9. Web Safe Colour Chart
10. Browser Safe Colour Chart
11. Approximate Conversion from Points to Pixels
12. Web-safe-font-cheat-sheet-v-2-including-google-font-api
13. 25?point Website Usability Checklist
14. Will the browser apply the rule(s)?
15. When can I use? Compatibility tables (html5, css3 + +)
16. The Web Developer’s SEO Cheat Sheet