After signup, the url for logging in is https://jasminepm.cloudforce.com

To change your username, goto:
Your Name->Setup->My Personal Information->Edit->Username

Change your timezone, goto:
Your Name->Setup->My Personal Information->Edit->Time Zone

Set your work hours, goto:
Your Name->Setup->Develop->Custom Settings->"Manage" Calendar Config->Edit
- Day Start
- Day End

Turn off Salesforce newsletter Your Name->Setup->My Personal Information->Edit->salesforce.com Newsletter Settings

Here is a link to a screen cast which covers this quick start:  http://youtu.be/JTV9syrbFCQ