Did you read the warning? It pretty much answers your question:

"This may mean that the server has generated its own security credentials, which Google Chrome cannot rely on for identity information, or an attacker may be trying to intercept your communications."

I just want to ensure the user that information passed to/from the server is encrypted.

Self-signed certificate doesn't guarantee the encrypted communication to/from your server. An attacker can intercept your handshake request and provide their own self-signed certificate.

You can create your own CA, sign a server certificate with it, and then ask users to install your CA certificate into their browsers.

Or you can get a free certificate from StartSSL.

Alternatively, you can contribute to some replacement for TLS.