I have used a pocket notebook ever since I got my first car in 199x LOL something my father always said was if you take care of your car your car will take care of you. I used to do most of my own general maintenance but with newer cars, corresponding warranties, as well as time constraints due to work it is just easier to take it to my friend's shop. I still have my little notepad, but now I also utilize mycarfax. If you take your vehicle to the shop the service records will automatically be added, or if you do your own you can manually add it. Service records follow the vehicle by VIN so if you sell it the next owner if they use it will have access to all the records.