Products are services or goods being provided. They can be added to opportunities, quotes, sales orders, and invoices.

To create a product, navigate to the Products module.

Click New.

Enter all details, including pricing information and click Save.

This product is now ready to be added as a line item.

To add a product to opportunities, quotes, sales orders, or an invoice, open the record for which you will be adding the products.

Scroll down to the products section of that record.

Click Edit Line Items.

Click the dropdown box under Products and begin typing the name of the product.

Once it appears, select it. 

Enter the quantity. This will affect the grand total based on the set prices for the product.

You can add as many line items as you would like. Once you are done, click Save Line Items.