@Aaron McGinnis, if you're doing hundreds of entries per month you're beyond the scope of what I was talking about. Frankly, if your company is doing hundreds you're not going to be on BiggerPockets at all. My system is a basically the same as the old 2 column paper ledger, just in Excel so you don't have to add it yourself. You are correct that it doesn't scale if you get employees but it's because of audit trails and controls and employee taxes. A spreadsheet doesn't offer the ability to see who is making or editing entries so it's high risk for fraud and computing payroll taxes is a freaking nightmare. Once you have an employee, get an accounting system that has payroll plug ins. Loading historical data in is something your accountant should be able to do very easily. Yes, you'll have to learn a new program but you'll already have your accounting system down.
To go beyond the scope of the forum question, if you do get an employee, get a pro to help you set up business processes to make sure they can't defraud you blind. Reconciling cash accounts and approved vendor lists is a huge thing that everyone should do. Also, don't be afraid of subledgers. My rent receivables is it's own form, lets me track a lot of details about rents, renters, dates, notes, etc without blowing up the ledger with stuff it doesn't need. At the end of the month I just record the totals to the ledger. If you're doing 2 house flips and need to keep the expenses seperate just keep subledgers for each then record the totals to the ledger. Also, don't be afraid of recording things at a higher level. I make an entry for the lowes bill, not for every blind and board I buy.