Unknown Commands

So, I've recently set up the basic, latest server. Seems to run fine, no connections issues anyway. But none of the commands have any effect (yes, I am listed as the op). It's claimed on the main dl page that the basic commands work 'out of the box' as they put it, so I assumed there wasn't something additional I had to do.

Regardless of the command I attempt to use (I type them directly from the list of commands linked to that page that says useable 'out of the box'), not a single one is recognized. Any command returns a 'unknown command' error.

I am rather new to this, and could easily be missing something. After perusing every Goggle hit I could find on the subject (not many, really), I wound up here. The 'help' on those few hits I got consist of pages full of Java with little to no explanation of what it's supposed to do/mean, where it's placed, etc.

I use no plugins as yet, need no particular permissions, etc so haven't messed with that (it's only one other friend and myself on the server). I changed only what would spawn or not, and added us to 'ops'. No other changes were made.

Any help on what's going on here would be greatly appreciated! thx