Two very different questions. As for the second one, try starting here.
www.tokyowithkids.com
Use the discussions or FYI links to steer you to the right sections.
As for the first question, friend of mine had a J girlfriend who was a social worker. Pretty dreary job. I think her "training" amounted to having a BA degree, then getting trained/experienced in whatever sector she was in, on the job. Ex. nursing home work meant changing bedpans.