Pau is a pretty small town, and it is unlike that you will really need to use public transportation to get around, unless you are really going far afield or you have mobility issues. Still, it can be a bad hike to get from the train station up to the Castle area, and it is a good idea to use the funicular. It's free, it gives you a good view of the mountains and it is a well-maintained old vehicle. A great introduction to the city, and a pretty unique mode of transit.
Pau is located in the South west corner of France, 700 km from Paris. Driving to Pau from Paris is quite long and one may have to consider air transport or train.
Pau airport is a rather small one; it has 10daily Air France flights to Paris (Orly and Roissy) and 3 daily flights to Lyon.
Many British and North European have more and more Bearn as destination very often to look for country houses, mild winters, and low cost companies operate on the Pau airport.
Transavia has 4 flights a week from Amsterdam and Ryan has a daily flight from London.
The local chamber of commerce and industry actively promotes the development of the airport. Check the website for companies and schedules.
Important serious tip: when checking in for a Pau-bound flight, make sure you get a seat on the left side: when approaching and landing (well, with fine weather) you will have a wonderful view over the Pyrenees.
Look at the snow-capped mountains in the background on the Pau airport picture.
And arriving at sun set is not bad as well; picture is not good, but gives an idea of what can be expected.
Travelling by train is now a good option with the TGV (Train à Grande Vitesse) which is a very good means to get to Aquitaine from Paris (Bordeaux is at 3 hours from Paris, Pau 5 hours).
There are several of these buses in Pau, and they are very timely and reliable means of moving from point to point.
Though I have a personal car for these trip, but these buses are very visible all about the town.
For an eight hours drive, I decided to take a confortable car. So, driving from Paris to PAU was done with leisure, and it was an exciting trip.
The Volvo S80 was very comfortable and reliable trought the trip to, and from PAU.
BECAUSE WE DO NOT KNOW OUR WAY AROUND THE FIRST DAY, THE LOCAL AUTHORITIES WERE VERY KIND TO GIVE US A DRIVER AND THIS CAR TO TAKE US AROUND OUR OBJECTIVE LOCATIONS.