Installing plugins
It is very tempting to download every interesting plugin and try them all at once. Don't. If something does go wrong, then it is very difficult to figure out which plugin is causing the problem. The best way to try out new plugins is to methodically add one at a time, exploring the functionality of the plugin before moving on to the next one. As you do this, you may want to take notes about user interface details that you would like to change or features that you would like to add or modify. These notes will help you later to prioritize and estimate the amount of effort involved in getting your site up and running.
Test server
Testing new plugins is not conducive to running a stable site. It is always best to test plugins on a test server. You should never try new plugins on a production site. Make a mistake with your production site and your visitors could be greeted by an empty white screen. Always test any changes on a test site before deploying them to a production site...
