Where can I try out (demo) CiviCRM before I install?
CiviCRM has demo installs where you can "click around" and try things out:
Login as demo with password demo.
If you get an "access denied" message, clear your cookies and cache and then login, or try a different browser.
In addition, the sandbox at http://sandbox.devel.civicrm.org/ allows community members and developers to explore new features in upcoming (Alpha) releases and help identify bugs in the release prior to the Beta launch.