A new hope

There will be a change, a new start.

On Friday I had a second job interview, they offered me the job. I took the contract home with me to read it, sign it and send it back.
It all went very fast and very good. "Too good to be true", a little suspicious voice inside me thinks.

Actually when I decided to start applying I planned to go abroad. I thought it was a good time, I have some work experience, no partner, no pets and I feel lonely and out of place where I live now anyway. I wanted to go to Ireland or UK.
A search didn't turn up a lot of suitable jobs though, it seemed that mostly companies seemed to look for more work experience.
Instead I found this company (belonging to the same corporation at the one I work for now) looking for a usability expert. I am none, but I 'd like to be, so I applied. Now they hired me for another job, process manager. A smaller step maybe, but non the less a step. A step away from programming and coding, towards more project management and conceptual work.
People seem to be really nice there. Apparently they liked my somewhat "freakish" personality.

This is my first time changing jobs. It's the first time quitting a job. It's the first time completely moving from one place to another.
The doubts and the worries are now kicking in.
What do I do next? When and how do I quit my job? How do I tell my team leader that he'll lose another employee when another one who'll quit isn't even replaced yet? Until when do I have to terminate the rental contract? How do I find a new place to live? How do I move? Do I have to renovate my old flat? How much will it all cost? Where to do I have to send notices of me moving? How will work feel after everyone knows I resigned from my job? How will the new job be? Will I be able to make friends? Will the work be good and interesting and will I be able to handle it all?
All these questions and more go through my head. I'm trying to calm down and think in little steps. What has to be done next?