Information Week has published a quick, convenient list of 5 tips that you can use to keep you Google searches private and protect your online searching and surfing. The Google search privacy tips include:
1. Delete Your History
2. Clear Out Your Cache
3. Bust Your Cookies
4. Use an Anonymous Surfing Tool
5. Rethink Your Search Strategies
The article goes into specific details on each privacy search tip. You can read the entire article @ Five Ways To Keep Your Google Searches Private.