The employment contract
You have found a job at a Dutch employer. With your employer you have a labour agreement. For example, in this contract are the rules for working hours, wages, vacation, leave.
Next to your contract is often a collective labour agreement (CAO). It contains the additional rules for all workers in the sector over pay or wage for sickness.
Also, you get also 8% holiday pay above your gross salary.
Applying for the social security number (BSN number)
The application of a citizen service number (BSN) is required; This is a similar number as the NIE in Spain. The number you get to the IRS and you need to communicate it to the employer.
Other important matters: