You probably got npm because you want to install stuff.
The very first thing you will most likely want to run in any node program is npm install to install its dependencies.
You can also run npm install blerg to install the latest version of "blerg". Check out npm install for more info. It can do a lot of stuff.
Use the npm search command to show everything that's available in the public registry. Use npm ls to show everything you've installed.
If a package lists a dependency using a git URL, npm will install that dependency using the git command and will generate an error if it is not installed.
If one of the packages npm tries to install is a native node module and requires compiling of C++ Code, npm will use node-gyp for that task. For a Unix system, node-gyp needs Python, make and a buildchain like GCC. On Windows, Python and Microsoft Visual Studio C++ are needed. For more information visit the node-gyp repository and the node-gyp Wiki.
link: Links your current working code into Node's path, so that you don't have to reinstall every time you make a change. Use npm
link to do this.
install: It's a good idea to install things if you don't need the symbolic link. Especially, installing other peoples code from the registry is done via npm install
adduser: Create an account or log in. When you do this, npm will store credentials in the user config file.
publish: Use the npm publish command to upload your code to the registry.
npm is extremely configurable. It reads its configuration options from 5 places.
Command line switches: Set a config with --key val. All keys take a value, even if they are booleans (the config parser doesn't know what the options are at the time of parsing). If you do not provide a value (--key) then the option is set to boolean true.
Environment Variables: Set any config by prefixing the name in an environment variable with npm_config_. For example, export npm_config_key=val.
User Configs: The file at $HOME/.npmrc is an ini-formatted list of configs. If present, it is parsed. If the userconfig option is set in the cli or env, that file will be used instead.
Global Configs: The file found at ./etc/npmrc (relative to the global prefix will be parsed if it is found. See npm prefix for more info on the global prefix. If the globalconfig option is set in the cli, env, or user config, then that file is parsed instead.
Defaults: npm's default configuration options are defined in lib/utils/config-defs.js. These must not be changed.