what exactly do i need other than the application form?

According to related department in China, the minimum age should be 18. However, the applicants are required to provide their diplomas and working experiences proofs for applying the work permit. And you need to ask assitance from your employer to help you apply for the work permit. It is done at local labor bureau. There are many required documents, such as your working experience proofs, your diploma, contract, your employer's business license. I would suggest you ask your employer to consult with the labor bureau first.

After getting the work permit, you can apply for the Z type. You should provide your passport, application form and your work permit. When you come to China, you need to change your work permit to employment certificate and then apply for resident permit for your employment.

I personally suggest that your employer may find an agent to help you acquire the work permit and change it to a resident permit. The agent is very familiar with the process and procedure.