If you have the QB program then click on Help at the top menu bar and on Help Index and look under the topic:
manufacturing representatives, managing your business and read everything found there. It sounds like you need to select a Non-Retail Sales type business but I don't know all the details.Do you pay sales taxes on the sales or does the manufacturer? Do you actually pay for the merchandise or do you just get a commission from the manufacturer?
On Service, Inventory and Non-Inventory type items you can create a two-sided item (to use for both purchases and sales so you can run item profitability reports) by clicking the small box on the item setup screen that says This Item is purchased for and sold to a specific customer. This opens the purchase side where you can enter the account you track these purchases in (a Cost of Goods type account) as well as the sales info. For an Other Charge type item there is a box that says This is a reimbursable charge that you check to open the purchase side of that screen. This is the same in both verisions, I believe.