Pyrenees crossing

Hi, I'm going to be travelling from san Sebastian up the west coast of France , which is the best way to cross over the Pyrenees. Paul.

Follow the motorway towards France, and cross the border at Irun, proceeding up the western side of France past Biarritz and Bayonne. You won’t actually cross over the Pyrennes unless you specifically wish to, in which case you can take a detour. 

Enjoy, sounds good.

Those roads can be busy and confusing. If it's your first time I would use the toll road near the coast as it's easier. However if you're adventurous set your satnav to avoid tolls and you'll come up the old road through the redundant customs post and supermarkets. Once in France there are options and avoiding tolls is not too bad. If you head inland the N121and (a) are scenic and further away but equally good is the Somport tunnel, again worthwhile.
Good luck.
Rich..

Thankyou for your  advice,  much appreciated.  Paul.

We drove up the toll road a month ago which will take you easily into France without too much climbing, but we turned off after Irun towards Sare and up to Col d’Ibardin ( right on the border and loads of cheap booze!) 
Sare is a very pretty village to stop at, loads of restaurants and an impressive church then a nice drive up to the Col
There are a few more roads through the Pyrenees in that area that are well worth the detour from the main roads.

If you've got the time and inclination drive further east and take in the fantastic scenery before tackling some of the mountain passes head for Jaca and head up the E-7 or if a little more adventurous go just a bit further east to Sabinanigo up the A-136. Both these routes would provide views and experiences you'll talk about for ever.