I'll take an initial stab at this. CW, feel free to modify.
What should the title of the question be?
The title must contain the issuing patent authority, serial number and the summary of the patent. Indicate that you want to challenge the patent by predicating the title with the word 'Challenge'. Per your example patent, the title would be:
Challenge US 20090293106 "Method and apparatus for controlling wireless network access privileges"
This serves some key purposes:
Search engines quickly see it, and put your challenge in front of other people that feel that the patent has no merit
Anyone familiar with the patent can quickly see it on a a list of questions
Anyone with domain knowledge, but perhaps not familiar with the patent will see that it's something they may be interested in viewing.
What should I include in the question?
The question should open with a summary of why you think the patent is invalid. What specific claims does it make that you disagree with? Why do you disagree with them?
You should also tell us why you care about this patent. What precisely does it cover, what are the possible ramifications of not challenging it?
What tags should I use?
Do tag the question with the patent or publication number per the FAQ. In this case, use the tag us20090293106.
Do tag the question prior-art if the question is specifically a request for prior art. One of the goals of the site is to identify and submit prior art to the USPTO in accordance with the AIA (America Invents Act).
Do tag the question with more general categories that others might subscribe to. For this example, tags like wireless-networks or information-security (the USPTO's classification) might be useful.
Don't invent more tags than you need.
How much work do I have to do myself looking for prior art before I submit the question?
As much as possible. Presumably if you're convinced that an application is "stupid" you must have a pretty concrete idea of exactly what prior art invalidates it. You should tell us what that is and where you found it. A link to the art itself (not a discussion of the art) is essential. And remember: the art you have in mind must have existed prior to the time of filing. In fast-moving fields, many inventions that would not be new now, were new in the surprisingly recent past.
The end of your question is where our work begins, so it really does need to include some starting points.