salesforce.com provide various cheat sheets, covering Apex code, Visualforce, Chatter, the Force.com SOAP API, formulas and GitHub, that are concise reference guides to each of these technologies.
Salesforce Cheat Sheets
The number of cheat sheets provided seems to be increasing all the time and are so useful as they summarize the most important aspects of each technology in a compact, searchable and printable form.
They now provide the following cheat sheets:
- Collaboration: Chatter Cheat Sheets
- App Logic: Apex Code Cheat Sheet
- User Interface: Visualforce Cheat Sheet
- Integration: SOAP API Cheat Sheet
- Integration: REST API Cheat Sheet
- Security Cheat Sheet
- App Logic: Formulas Cheat Sheet
- Tooling: GitHub Cheat Sheet
The online cheat sheets are always up to date, and new ones added to include the most important reference material. You can either print the cheat sheets, or view them online.
Enjoy!
Setupforce.com - The Salesforce.com Setup Blog 