My husband owned a retail business for 20 years. He wrote about 100 checks a month, including payroll. He made about 30 petty cash payments a month. I did all his bookkeeping, but not bill paying.
I would file by month. As items are entered into your bookkeeping/accounting system, file them in that month's folder. A few major suppliers may merit their own folder, but for the most part, you should be able to find a document you need when filed this way. Most documents once entered into the accounting system do not need to be retrieved.
Petty cash chits/receipts should be accumulated in a separate folder or envelope for the month with a running list of what's in it. Petty cash payments tend to be for a limited set of expenses. Once you gain some experience with your specific business, you can create a spreadsheet for petty cash where each line contains the date, the vendor, a column for each of the common expenses from your chart of accounts (for example, Office Supplies, Merchandise, Repairs, Cleaning, etc.) and total. Go ahead and break out the receipt across the accounts when you enter it on the list . Or if you're rushed, at least put the date, vendor and total. Asterisk it to know you need to come back and break it out. Most receipts during the month will fall under a single category and are easy to do. Then, once a month, total, reimburse the petty cash account and enter the total by account into your accounting system. At that point the petty cash envelope can be filed in your monthly folder or folder can be filed behind your monthly folder and a new one started for the next month.
Invoices: The amount of the invoice goes in your accounting system (paid or accounts payable) and the physical invoice goes in the monthly folder. Write the check number and the date and the amount paid (if not obvious) on the document.
Receipts: Go in the petty cash folder/envelope and the purchase information gets handwritten on the spreadsheet.
Delivery Notes: Are these packing slips? They can be stapled to the invoices. Discrepencies in amount received vs. amount on the slip need to be noted and communicated to the vendor. If you are waiting for a credit, these can be in an @WF folder.
Correspondance: Depends on how much of it you have. If it's rare, you could file it with the invoices OR have one folder for the whole year.