I suggest contacting the Council of British International Schools as they will be able to supply you with a list of accredited British International Schools in the California area.
For a general overview of the schooling system in San Jose, have a read of our Education and Schools in San Jose page. San Jose is part of the Greater San Francisco Bay Area, and depending on where in the city you will be living, it may also be worth considering schools in San Francisco.
I also suggest speaking direclty to your husband's company, as I am sure they are used to assisting their expatriate staff relocate to the city and will be able to point you in the right direction in terms of schools in the city, as well as the areas to consider finding accommodation, as this is an important aspect related to finding the right school as you'll need to consider the transport/traffic to get to and from school as well.
All the best with your school search and relocation to San Jose!