Income and Accounts Receivable

Please let me know if I am doing this correctly
We have a customer and an invoice for them ( which I entered into sales invoice)
The payments we are receiving from this customer is our income ( which I created a category under income called operation funds) into the business, but this customer is paying installments. Do I enter the payment we are receiving under income (operation funds)? and if so how do I also show the installment payments we are receiving to reflect against the balance of the invoice in accounts receivable?

There are several avenues. The easiest is to View the sales invoice and click Receive Money. Edit the full amount of the invoice to be the amount of the payment. Manager will apply the payment to that invoice and keep track of the remaining balance due. This, of course, assumes that when you created the sales invoice you allocated the appropriate line item to the income account you mentioned.

Another way is, in a selected cash account, Receive Money and allocate to Accounts receivable and the subaccount for the specific invoice (which appears after Accounts receivable is selected).