user vs. root in node and npm installations

I'm experiencing problems trying to install node and npm apps. Typically trying to setup new apps with yo and generator-angular.

I've installed yeoman (sudo npm install -g yo) I've installed generator-angular (sudo npm install -g generator-angular).

However when trying to create a new app with the generator I get rights issues. yo angular temp (for example).

When investigating, I don't understand why the .npm folder in my user directory has some folders created as the root user.

I'm on mac, Mavericks.

Is there a specific way to install node and the rest. In terms of sudo / root / user priviledges ?

I've completely reinstalled node, by downlading 0.10.26 form the nodejs.org website.