I bought the game and am wondering how I can be assured I am playing the latest version, or where new updates/versions will be posted? Thanks

New versions (and other updates) are posted fairly infrequently on the Dev Log, which you can subscribe to through either RSS or the email mailing list.

The newest version will also always be up on the download page.

In general, if you're planning on sticking around the forums, there's a rather large hullabaloo around the time any new builds get released.

However, this is seldom a very frequent occurrence. Like, years can go by. So, don't hold your breath.