Non-Inventory Items
You can add non-inventory items to orders one of two ways.
1) Enter in just a description for line items that won't pull from inventory. Since the line won't be linked to an item, no inventory activity will occur. Simply type the line details in the Description box.
2) Create items (Inventory -> Items -> New Item) for things you'd like to add to orders and invoices, but that won't require inventory level tracking, and mark the Inventory Type as Other Charges. Other Charges items can have pricing and a sales account assigned, but won't deduct from inventory.