Added to README.md.

Author: toolness

README.md

@@ -6,10 +6,10 @@ This is a simple Web application that, for any URL path, serves the
 contents of an Etherpad with the same path with the MIME type
 `text/html`.
 
-For example, if the application is served from `htmlpad.org` and the
+For example, if the application is served from htmlpad.org and the
 Etherpad backend it's configured to use is at
-`etherpad.mozilla.org:9000`, then visiting `http://htmlpad.org/foo`
-will deliver the contents of `http://etherpad.mozilla.org:9000/foo` as
+etherpad.mozilla.org:9000, then visiting http://htmlpad.org/foo
+will deliver the contents of http://etherpad.mozilla.org:9000/foo as
 HTML.
 
 This effectively allows people to easily collaborate on writing HTML,
@@ -18,11 +18,29 @@ out, seeing how it looks in the browser, and sharing it with others.
 
 ### Installation ###
 
-Just run `python manage.py runserver` and open your browser to [http://localhost:8000](http://localhost:8000).
+Just run `python manage.py runserver` and open your browser to [http://localhost:8000](http://localhost:8000). As you save changes to HTMLpad's source code, the server will automatically apply them, allowing you to iterate quickly.
+
+### Troubleshooting ###
+
+While HTMLpad is a Django application, you don't need to have Django installed system-wide. That's because running `manage.py` automatically creates a virtual environment, downloads and installs the appropriate version of Django and any other dependencies, and activates the virtual environment for the duration of the script.
+
+However, this can sometimes result in a broken virtual environment, particularly if `manage.py` is aborted while it's still setting things up. If anything goes amiss, try wiping the `.virtualenv` directory and try again.
 
 ### Deployment ###
 
+You can run `python setup.py install` to install the `htmlpad` Django application package into any environment, including virtual ones.
+
+This Django application assumes the following custom settings variables:
+
+* `HTMLPAD_ROOT` is the string prefix, including any trailing slash but no leading slash, of the HTMLpad instance on the Web server. It can be an empty string. For example, if a user browses to http://foo.com/mypad/ to access your HTMLpad's root, then the setting's value is `'mypad/'`.
+
+* `ETHERPAD_HOST` is the Etherpad instance that your HTMLpad delegates to, formatted as a hostname:port string.
+
 See the [hackasaurus-puppet-data][] repository for Puppet deployment files.
 
+### Security Considerations ###
+
+Because the HTMLpad simply delivers universally-writeable Etherpad content as raw HTML, an HTMLpad instance should probably be served on its own dedicated domain.
+
   [hackasaurus-puppet-data]: https://github.com/toolness/hackasaurus-puppet-data
   [Atul Varma]: http://toolness.com