I like Stephanie Palmer and she generally has good information and advice.
But I disagree that querying is useless. I have spoken with and interviewed dozens of managers and they all sometimes look at queries (less so agents). Is it a long shot? Yes. Do you increase your odds by winning the Nicholl fellowship or having a strong referral? Yes, of course. But I know writers that have gotten repped by query emails, so it can work.
The keys?
1) Keep it brief. No more than a few sentences and your logline. Too long and they won't read it.
2) The logline is key. If your logline is fantastic, they might request the script. If you don't get any response, chances are they didn't like your logline. DO NOT send a synopsis! Just a one (maybe two) sentence logline. That's it.
3) Make it personal. I've seen plenty of obviously mass emailed queries "Dear Sir or Madam" or even with the wrong name. Will it take longer to send out? Yes. But nothing will make them delete faster than a generic email they know you've send to a hundred other people.
4) Have an amazing script. I can't emphasize that enough. If your script is good, make it better. Once you get a read request, if you don't have the goods, you've wasted that opportunity. There is very little chance they'll read it a second time, even if you rewrite it to make it better.
If you want to read/listen to some of the interviews I've done with lit agents and managers, you can find a list, here:
http://www.scriptsandscribes.com/agentsmanagers/
Good luck to you and I respect the fact that you're waiting to query until your scripts are ready! Way too many writers query way before they should.