Getting the paperwork done...tramites (Buenos Aires)

Hello to everybody, I just arrived to this amazing city with an intent to stay for a while. I brought all necesary paperwork for getting temporary residence from my home country, but now it seem to be little tricky. In order to get a job you need to obtain CUIL, but you can't get one unless you have a pre-contract from your employer. Anybody with any experience related to this subject or advice?