WV state tax (primary residence) for military based in California (PCS'd in June 2016). 1) Do I pay state tax? 2) Any special forms related to taxes for PCS?

There are no forms that need to be file due to a Permanent Change of Station (PCS).  If you were a West Virginia resident you will remain a West Virginia resident unless and until you change your State of Legal Residence (SLR).  SLR is considered your permanent home, the state where you intend to live after you leave the military. This state is considered your residency for state income tax purposes. In addition, state of legal record is used to determine qualification for in-state tuition rates, eligibility to vote for federal and state elections and for a will to be probated.  It does not automatically change when you're assigned to a duty station in a different state.

SLR may be changed with your approval at any time during your military career. To change the state of legal residence, you should submit paperwork (DD Form 2058 or State of Legal Residence certificate) to your finance officer. Once submitted and approved, SLR status can be changed, but may need validation or proof such as a written letter stating your position, a driver's license, voter registration or a vehicle registration for a new state.

Only your state of legal residence may tax your military pay, thanks to the Servicemembers Civil Relief Act, which prevents a state from taxing military pay just because a servicemember lives within the borders of that state. However, any non-military pay earned in the state you're stationed in is subject to income tax requirement in the state where it was earned.

You will file a West Virgina resident return.  If you earned non-military income in California you will have to file a California non-resident tax return.  If you did not, you do not need to file a California tax return.