Very New At This

I purchased a new AppleTV (Black) yesterday from the Apple store here in Florida.

I am a bit confused as to how to proceed with putting ATV Flash on it.

First, I need to jailbreak the unit yes? Then after that run the ATVFlash program and it will put that on it wirelessly yes?

But before the ATVFlash is installed I have to jailbreak the unit first with SeasonPass yes?

In the directions to SeasonPass it gives two options. One untethered and one tethered yes?

So, if you do it the untethered way at some point you have to attach the mini-cable from your Mac to the AppleTV yes? Doesn't that make it tethered?

Also it seems that everyone posting here is having a lot of trouble  jail breaking their units. Has anyone come up with a sure fire way to do this?

Ok, so now I have the unit jailbroken. Do I keep going and do the tethered instructions or is it done and I can run ATVFlash on it? Or am I ready to install ATVFlash?

Also it seems that some people here do the 7 second thing plugged in, not plugged it and one guy even had his on his lap and did it. What is the best way? The makers of ATVFlash say NOT to have power to the unit, others say it won't work unless it is plugged in. WHat is the best, tried and true way to do it?

Thanks and thanks for (hopfully) answering my newbie questions.