After you've created your Products and Price Books, you will need to connect them to your Opportunities before you can start generating Quotes. Start by assigning a Price Book to an Opportunity.
How to assign a Price Book to an Opportunity
- Open an Opportunity. Go to the Related tab.
- Scroll down to Products and click Set Price Book.
- Choose a Price Book from the dropdown. Click Save.
From here, you can start adding Products. The value of your Opportunity will be updated to reflect the value of the Products you've selected. You cannot manually edit the Opportunity Value unless you delete the Products you've added.
After that, you can create a Quote and add additional discounts, alter the quantity, and adjust the sales price before sending it to your customer. If you sync the Quote, you will no longer be able to manually update your Opportunity value.