Hi, Yes, it will take just under two weeks to get your work permit. The immigration office will give you a date to attend the hospital to give blood. The hospital will give you a date for the medical with the doctor. It all takes time. Do not worry we were all very cconfused with the system the first time.
You MUST bring your police report from the UK. Apply to your local police station for details held under the Data Protection Act, It cost £10 last year. Do not aply for it until about September as it must be under 3 months old when you present it to immigration.
It sounds difficult but you will have a great time if you do the whole season. Stick at it.