There are common issues that arise within the community of small businesses that use QuickBooks. Jennifer Johnson, MSAcc, created a series of books about these issues after working for and in that community, with real clients in real business settings.
The series is called Get More from QuickBooks and has four volumes:
Reasonably priced from $5.99 to $9.99 or free if you have Kindle Unlimited. Get them on Amazon:
Volume 1: Find and Fix 27 Common Problem in QuickBooks
Volume 2: Reconciling Tips, Tricks, and Traps (to Avoid) in QuickBooks
Volume 3: Learn the Modern Method for Customer Prepayments in QuickBooks
Volume 4: Inventory and Cost of Goods Sold (COGS) in QuickBooks