We always travel with our two girls - Jayne (the Jack Russell), and Pipi (the Chihuahua). Sure, travelling with your pet, or pets, can present a few challenges, but a bit of thought and planning will ensure that all of you will have a great trip.
Before setting off - don't forget to pack your pet's bedding, favorite toy, food, water & food bowls, leads, medications (a pet-specific first aid kit is a good idea), paperwork (Vaccination card, etc). Make sure their vaccinations are up to date, and see the vet for advice on treating travel sickness, insect bites, etc. Don't forget to pack a good supply of "pooh" bags either! Check that your pet will be welcome at your intended destination.
On the Road - strap them in securely, make regular comfort stops for toilet breaks, exercise, a drink and a snack. Fresh air is also important, as is a comfortable place to snooze. Never leave them unattended in a locked car (especially if you are 'outback' - summer temperatures can kill a small animal in next to no time).
At the Camp/Park - make yourself aware of, and comply with, any pet policies or rules. Always keep your pet under control at all times, do not leave them unattended. Make sure that they are comfortable in their temporary accomodation, and make appropriate arrangements for their care if you cannot take them with you for the day - many local vets offer a day-care service, or you could try recruiting a local pet-sitter. Get to know the local rules - are there any off-leash areas available (or are there any restricted areas to keep away from). Give your pet as much exercise as they would get at home, if possible (and allowed by other pet owners) socialise you pet with others in the area. Always clean up after you pet (remember the 'pooh' bags?