I scheduled everything on the calender in Microsoft Outlook. I'd change the view to "today" and print it, which gave me the detail of the current day. Then I'd change the view to "month" and print that also, so if I scheduled anything while I was out I'd have the next 30 days in front of me. I kept both sheets on my clipboard. If I scheduled a new appointment while I was out on the truck, I'd write in the new appointment on the "month" calendar and update Outlook when I got back to the office. The next day, I'd print the same two sheets (today and month).
I know there are more sophisticated scheduling programs available, but my PC already had Outlook (most do) and I was looking to save money.