Obviously the first tester group would be your own group. But beyond that? It would seem to make sense to have at least more than one group test out your game, as different groups want different things and play differently. Fresh eyes find different bugs, etc. etc.
Are there resources out there to help aspiring game designers without a lot of contacts find people willing and eager to test out their game?
Or is this in essence a "find players in general" issue?
To clarify my own situation: I have the mechanics finished. The setting is still under development, but in accordance with the motto "fail faster" I want to go ahead and test the mechanics (in a different setting for now) to see if they work and are fun or if I need to go back to the drawing board. I have a sort-of group, but I don't know them very well and they don't meet often, and so I'm not excited about the prospect of presenting the mechanics to them right now (as I'm sure there are a dozen issues I've overlooked). Also, I'd like to test the game (including the setting, later) on more than one group, as mentioned above. I've put out some feelers among my current friends and acquaintances, but nobody's really been excited about playtesting or even really giving in-depth feedback, and I don't want to be that person who's always shoving their project in your face. I'm willing to run something online as well. I'm also interested in having others run a game without me present, and giving me their feedback.
Also, I'm looking for something of a guide-type answer that might help someone besides just me.