Add this to your .bashrc or .bash_profile file:

alias blender='/Applications/Blender/blender.app/Contents/MacOS/blender'

To open a file on the command line:

blender file.blend

To render frame 10 from file.blend:

blender -b file.blend -f 10

To render the whole animation from file.blend:

blender -b file.blend -a

Path to Blender Add-Ons for Blender 2.xx:

On Mac

/Users/you/Library/Application Support/Blender/2.xx/scripts/addons

On Windows

C:\Users\you\AppData\Roaming\Blender Foundation\Blender.xx\scripts\addons

On Ubuntu

/home/you/.config/blender/2.xx/scripts/addons