What is the best way to go about setting up Beta Testing for an Interactive Fiction?
Releasing it and then just constantly updating it?
Releasing it as a file for others to download and comment on the forum?
Possibly releasing the Beta and Full Versions as two separate Games?
I'm just curious If I should even go about Beta Testing.
If anyone could share their thoughts on this, it would be awesome! Thanks.

I'd release them as separate games. Then post in the announcement section asking for feedback. Don't think there's any real convention.