Seeking advice on organizing my first playtest

I've been playtesting Dirty Secrets of late, and these are some of the things that I've learned along the way.

Take lots of notes on everything, especially the stuff that seems to break.
As far as possible, don't try to fix rules issues on the spot. Just write down what went wrong and move on.
Be aware of the roleplaying techniques that make your game work. You and your players bring assumptions to the table of how this roleplaying thing works. Make sure that you realize what they are. You may need to communicate some of them in your game text.
Be sure that you understand the desired effect of your rules. In playtesting Dirty Secrets in-house (in other words, with my wife and sister), I found myself saying, "I know that the answer that I want is such-and-such, but the game doesn't actually do that."
Know your playtesters. Get a sense of what games they like and don't like. Sometimes a design may be perfectly valid but someone just won't care for it. I know my current playtest group pretty well, but I have a short questionnaire for blind playtesters so that I can get a sense of their game preferences and their exposure to the genre that I'm working in.
Your playtesters are always right. Most of the time. What I mean by this is that, when your playtesters are describing their experience of the game, they are always correct. Don't try to convince them that they felt otherwise. Now, they may not know why they felt a certain way, and they may have no idea how to fix it, but their report of their subjective experience is always true.
Your playtesters are always wrong. Most of the time. Remember that you are the designer, not them. It's your job to have a creative vision, and it's their job to tell you how well you're doing at accomplishing it.
In my opinion, the first playtest should be for proof-of-concept. Is this thing generally working right? Only after you determine that your concept is essentially sound, then you should start stress-testing it. Do be sure to discuss this with your playtest group.
When a playtester puts stress on a game rule, thank him specifically. This is good discipline, because the first reaction is to yell and cuss. Grin!
Debrief after the game. Ask your playtesters what did and didn't work. Use open-ended questions first. (e.g. "What didn't work in the rules?") before homing in on specific issues (e.g. "I wasn't sure about the Violence system. Did you think that it worked?")
Did I mention that you should take lots of notes?
Thank your playtesters. Contrary to popular belief, playtesting is a hard and often thankless job. Consider that you're essentially asking them to play a broken game. So, appreciate the feedback that you get.

Post back here when you're done! We'd love to hear how it goes.