Typing vagrant from the command line will display a list of all available commands.

Be sure that you are in the same directory as the Vagrantfile when running these commands!
Creating a VM

vagrant init -- Initialize Vagrant with a Vagrantfile and ./.vagrant directory, using no specified base image. Before you can do vagrant up, you'll need to specify a base image in the Vagrantfile.
vagrant init <boxpath> -- Initialize Vagrant with a specific box. To find a box, go to the public Vagrant box catalog. When you find one you like, just replace it's name with boxpath. For example, vagrant init ubuntu/trusty64.

Starting a VM

vagrant up -- starts vagrant environment (also provisions only on the FIRST vagrant up)
vagrant resume -- resume a suspended machine (vagrant up works just fine for this as well)
vagrant provision -- forces reprovisioning of the vagrant machine
vagrant reload -- restarts vagrant machine, loads new Vagrantfile configuration
vagrant reload --provision -- restart the virtual machine and force provisioning

Getting into a VM

vagrant ssh -- connects to machine via SSH
vagrant ssh <boxname> -- If you give your box a name in your Vagrantfile, you can ssh into it with boxname. Works from any directory.

Stopping a VM

vagrant halt -- stops the vagrant machine
vagrant suspend -- suspends a virtual machine (remembers state)

Cleaning Up a VM

vagrant destroy -- stops and deletes all traces of the vagrant machine
vagrant destroy -f -- same as above, without confirmation

Boxes

vagrant box list -- see a list of all installed boxes on your computer
vagrant box add <name> <url> -- download a box image to your computer
vagrant box outdated -- check for updates vagrant box update
vagrant boxes remove <name> -- deletes a box from the machine
vagrant package -- packages a running virtualbox env in a reusable box

Saving Progress

-vagrant snapshot save [options] [vm-name] <name> -- vm-name is often default. Allows us to save so that we can rollback at a later time
Tips

vagrant -v -- get the vagrant version
vagrant status -- outputs status of the vagrant machine
vagrant global-status -- outputs status of all vagrant machines
vagrant global-status --prune -- same as above, but prunes invalid entries
vagrant provision --debug -- use the debug flag to increase the verbosity of the output
vagrant push -- yes, vagrant can be configured to deploy code!
vagrant up --provision | tee provision.log -- Runs vagrant up, forces provisioning and logs all output to a file

Plugins

vagrant-hostsupdater : $ vagrant plugin install vagrant-hostsupdater to update your /etc/hosts file automatically each time you start/stop your vagrant box.