For Federal taxes, you will need to withhold income tax (based off of their W4) and FICA from the employee's paycheck. You will also be subject to employer FICA and FUTA.
Washington has no state income tax, but you will be subject to state unemployment insurance and Industrial insurance (if applicable).
There can be complicated calculations and you do not want to get these wrong. I would suggest you either get payroll training or contract out your payroll service to a payroll processing company. Please let me know if you have further questions.
This does not answer my question. How much (percentage) of Social Security, Medicare; Federal; State; unemployment; and industrial insurance do I take out of each employee's check?
For payroll tax withholdings only: Social Security is 6.2% of first $106,800 wages of each employee. Medicare is 1.45% of all wages of each employee.
Income tax withheld will vary for each employee based off of their marital status and exemptions claims on their Form W4.
These are all the withholdings. FUTA and SUI are employer taxes and are not withheld from employees.
FUTA is 0.8% of first $7K in wages per an employee. SUI is different for each company. You will want to check with the state to see what your company's SUI rate is.