How do I modify sales, discount, and COGS accounts for new products?

Out of box, Connex will make no new products. If you enable create new under the products > missing products section, Connex will create them.

Should Connex make new products?

If non-inventory or service, then yes. If inventory, it should make no new items. Instead, map to existing items. For more info, read this guide.

How do I change the accounts?

If Connex is making new products and you want to change the accounts Connex uses, follow these steps:

1. Login to Connex.
2. Click manage.
3. Expand orders.
4. Expand new order and product accounts.
5. Adjust the accounts: 

My accounts are missing. What's wrong?

You need to refresh the list. Read this guide.

How do these accounts map to QuickBooks?

Here is a screenshot: