Employment Visa / Work Permit / Residency process in UAE

I am a bit confused about the rules and regulations regarding work permit and residency and Employment Visa in Dubai and I hope you can clarify some of the issues for me, I would very much appreciate it. I am a German national GP Dentist and I am currently in Dubai on a visit visa. I passed my DHA exam and received my eligibility letter, which entitles me to search for employment and be employed. I found a good job and agreed on the contract, which will be signed in a few days time. My questions now are: - what is the first step, application for residency or for work permit? And what is an Employment Visa? - do I have to exit UAE while waiting for an Employment Visa to be issued? If yes, how long does it take? I would like to know about the exact procedure and the approximate time frame, as I have to adjust to it and plan the coming months accordingly. Secondly I would like to ask if my degrees and any other documents need only the attestation by the UAE Embassy or is an attestation also needed from the Ministry of Foreign Affairs? Thank you for your help and I hope to hear from you soon. Best regards