Customizing Accounts, Contacts, or Activities

You can customize each of the standard tabs and types of records, including adding custom fields and setting page layouts. You can also customize search, tagging, and user interface options for your organization.

Navigate to the Setup
  1. Click on Your Name
  2. Go to Setup

To customize: Accounts, Contacts, OR Activites in the system

To customize: Accounts, Contacts, OR Activites in the system

Navigate to Setup | Customize.  Then click the standard object you wish to customize.  For example, Accounts, Contacts, Activities, etc.

Accounts

Accounts

Navigate to Setup | Customize | Accounts.  Customize the standard picklists, create custom fields and custom links, control the layout of fields, related lists, and custom links, and for Enterprise, Unlimited, and Developer Edition organizations, create record types and set up account teams.

 

Contacts

Contacts

Navigate to Setup | Customize | Contacts.  Customize the standard picklists, create custom fields and custom links, control the layout of fields, related lists, and custom links, and create record types for Enterprise, Unlimited, and Developer Edition organizations.

Activities: Tasks | Events | Calendars

Activites ~ Events, Tasks, Calendars

Navigate to Setup | Customize | Activities or Events or Tasks

Customize various options for tasks and events such as fields, page layouts, record types, validation rules, search layouts, and buttons. Also, enable or disable functionality like activity reminder popups and recurring events.

See Force.com's Documentation: Customizing Activity Settings