Let's correct a mistaken idea you have. Your spouse can NEVER claim you as a dependent. You and your spouse can file a joint return even if you had little or no income, but you are not and cannot be claimed as his dependent.
As for a W-4 if you get a job:
https://www.irs.gov/individuals/tax-withholding-estimator
https://www.irs.gov/pub/irs-pdf/fw4.pdf