Within the quotation or the invoice you can either search on name or ID to add products. In case you want to hide the ID on your documents, you only need to send an email to our support team so that they can deactivate this feature for you.
If you want to calculate different prices for different customers, Teamleader offers the option of pricelists. And if you want to offer different prices based on the amount your clients buy, then the option of graduated prices could be something worth discussing.
You are now all set for products. Check here for an overview of all articles on how to get started with Teamleader.