Transport
Peru has a wide range of transportation, partly because having a car is expensive so most Peruvians don’t have cars. Public transport is plentiful and cheap but can be difficult if you don’t know Spanish.
Check out my Transportation Tips for Peru, published by World Nomads.
Car rental
I recommend renting a car with hesitation. Peru is not an easy country to drive in because of a general lack of drivers who follow traffic rules. I have rented a car at the Lima airport to drive to Paracas National Reserve, which worked well. However, driving in and out of Lima was difficult because of traffic and a lack of signs for directions.