http://howtonode.org/introduction-to-npm
Oustanding little introduction to npm and how to use it. One trick, give your user access to /usr/local/ or /usr/lib/node_modules/ so npm doesn't need sudo. Nice.
http://demos.thejit.org/example/rgraph/example1/
A really cool deb / apt package dependency visualiser. It's a demo, but can be used by running "PageController.makeRequestAndPlot('PackageName');" in a firebug console.
http://packages.ubuntu.com/
The Ubuntu package list. One can find .debs to download here.