This article shows you how to log a call in Salesforce.
Generally calls are only logged in Salesforce if there's important information about a Contact or Organisation that you'd like to retain from the call (regarding an Opportunity or Lead, for example), or if there's a follow up action as an outcome of the call.
It's a good idea to come up with some internal rules about what sort of calls need to be logged and what other records might also be created as the result of a phone call (Leads, Contacts, Cases, Opportunities, etc.)
Logging a Call
Calls can be logged from any record in Salesforce where the Activity History Related List is visible. This is most commonly visible on Contact, Organisation, Lead, Case and Opportunity Records.
Log a Call Page Layout
The Log a Call Page Layout looks similar to the Task Page Layout. In the Task Information section at the top of the page you can add details of your call.
The Subject will default to Call, it's recommended that you leave it like this so you can easily identify Call Log records.
The Task Information section towards the bottom of the layout allows you to add a follow up task.
Click Save when you've added the necessary details.