If you use an American Express card, they cover insurance of the car (the rental car itself you still need standard liability insurance). It's called loss damage waiver. When they try to sell you on the rental car companies so called "no fault" insurance scam, you just decline, and use your Amex card to reserve and to pay for the car.
Also, on the Amex website, there is a travel section where they often have special rates that can be much better than Expedia, Travelocity, etc.
Better than taking notes, bring a camera and take pics of the car, before and after you return it.
I've had good experiences with Dollar, Hertz, and Budget. Some smaller companies have been less than satisfactory to downright horrible experience.
-Ed