You have entered into an employment relationship once you have agreed with the employer on the work you will be doing and the wages that you will be paid.
The labour legislation includes mandatory provisions which cannot be deviated from by agreement to the disadvantage of the employee.
The minimum terms of an employment relationship are determined in accordance to a generally binding collective agreement, if one exists in your sector. However, you can agree with your employer on terms that are more favourable than those laid down in the collective agreement.
You will find the entire labour legislation at the Ministry of Employment and the Economy's website.
If you encounter problems in an employment relationship, you can also have a look at the Occupational Safety and Health Administration's operating instructions.