In Sharepoint Designer select the library you want to add the workflow to.
Click on "List Worklfow" on the ribbon
Provide a Name for your workflow and an optional Description
In the workflow designer setup your workflow:
a. Add Action "send email"
b. Specify the email parameters you can use Lookups to search for values related to the item you have uploaded or modified. For instance in the field to you can select a Sharepoint Group or even the user who created the current item
c. In the body field you can insert values like Document Name, Title etc by clicking on add or change lookup
d. Add more actions as needed
Click on Workflow Settings in the Ribbon
Untick Allow this workflow to be started manually and enable on created and is changed.
Save the workflow by clicking the save button in the ribbon
Publish the workflow by clicking the publish button in the ribbon
Workflow should now be activated for that Library.