To speed up the process of entering data, default values can be set for Contact and Organisation types, and address, email, and phone types.
These defaults can be set as either a user defaults, system defaults, or both. User defaults take priority over system defaults.
User defaults are changed from the user preferences screen. This is accessed by clicking your username at the top right of the screen, then clicking preferences. Here you can set the default state and country when entering an address, and defaults for Contacts and Organisations
System defaults are set by editing the field in the custom fields manager. This is accessed from the System > Custom Fields > Create and Maintain menu.
Contact and Organisation types, and most custom fields have the option to set a default value. If a user has their own user default set, that will be used instead of the system default.