Classes and Jobs

I was wondering what jobs are from which classes. Can someone do a break down of the jobs from all the DoM/DoW classes? Can they be switched to and fro, just like the classes?
I'm trying to find out details about all this, unless there's a webpage somewhere

Class Q&A Guide. There'd also be information on all the various wikis etc.

Yes, you can switch back and forth between any job and/or any class you have available.