drush help si
Install Drupal using specified install profile.

Examples:
 site-install expert --locale=uk           (Re)install using the expert install profile. Set default language to Ukranian.
 site-install                              Install using the specified DB params.
 --db-url=mysql://root:pass@localhost:por
 t/dbname
 site-install --account-user=joe           Re-install with specified uid1 credentials.
 --account-pass=mom

Arguments:
 profile                                   the install profile you wish to run. defaults to 'default'

Options:
 db-url                                    A Drupal 5/6 style database URL. Only required for initial install - not re-install.
 db-prefix                                 An optional table prefix to use for initial install.
 account-name                              uid1 name. defaults to admin
 account-pass                              uid1 pass. defaults to admin
 account-mail                              uid1 email. defaults to admin@example.com
 locale                                    A short language code. Sets the default site language. Language files must already be
                                           present. You may use download command to get them.
 clean-url                                 Defaults to 1
 site-name                                 Defaults to Site-Install
 site-mail                                 From: for system mailings. Defaults to admin@example.com
 sites-subdir                              Name of directory under 'sites' which should be created if needed. Defaults to 'default'

Aliases: si