Kia ora! Welcome!

Hi! Thanks, kocio, for creating this subforum!
We can discuss, ask questions and share mapping ideas and specifics for the whenua of Aoteaora New Zealand here.

To summarise other places that are dedicated to OSM mapping in NZ, there is the WikiProject New Zealand on OSM wiki
There are also some rare posts coming up in a Google group NZopenGIS
And a mailing list Talk-NZ

Finally, there is also info about LINZ (Land Information NZ) data imports into OSM here on wiki - LINZ on OSM wiki

Have a good time mapping!

I’m reasonably new with OSM. I have used it in one web project. I’m based in Levin Horowhenua. Few things have changed around town, for example Mitre 10 has moved to different location. How would these kind of changes be done in OSM? Do I just edit? Is it going to be refreshed from LINZ map?

That’s basically it. You just edit. Go through the tutorial first, if you are completely new. There is also this site that covers most of the basics
There are no completely automated refreshes in OSM. Sometimes there are imports that are semi-automatically, semi-manually done, such as there have been an address information import from LINZ.
But all the mapping is done by users like you and me in general.

Any questions you encounter while mapping, my workflow is to first make a google search where I input my question preceded by “OSM” and it usually finds either a wiki page or a question in the help forum

Oh, also for building outlines, see my other forum post here - you can use rapID to speed up and make mapping buildings easy.

Happy mapping!