Not massively straightforward.

This article is just a placeholder until I get round to doing it properly – sorry if you were expecting more

1) From root run the git downloader

2) Do a symbolic link into domain folder

3) Setup subdomain in Dreamhost with fcgi. Set root folder to the domain/public

4) Setup database in Dreamhost

5) Setup dispatch.fcgi with database

6) Setup a config/configuration.yml file with email info

# Outgoing email settings

production:
 email_delivery:
 delivery_method: :smtp
 smtp_settings:
 tls: false
 enable_starttls_auto: false
 address: mail.xxxxxxx.xxx
 port: 587
 domain: xxxxxxx.xxx
 authentication: :plain
 user_name: postmaster@xxxxxxxx.xxx
 password: yyyyyyyyy
 openssl_verify_mode: none

7) Add entries into  public/.htaccess file – remove rewrite to folders like style and images, javascript and themes

RewriteEngine On
RewriteCond %{REQUEST_URI} ^/themes.*
RewriteRule .* - [L]

RewriteCond %{REQUEST_URI} ^/javascript.*
RewriteRule .* - [L]

RewriteCond %{REQUEST_URI} ^/stylesheets.*
RewriteRule .* - [L]

RewriteCond %{REQUEST_URI} ^/images.*
RewriteRule .* - [L]

8) Install as per instructions on Redmine site

9) That is all so far