Rule 1 is wrong!!!! Is Right
Having played the role of both PM and customer in a few large and small scale development efforts for a large North American exchange, I know that rule one is know the source of the requirements and to consult with them often. Negotiating deliverables and setting expectations is the only way to deliver a product that will make the customer happy. When possible have the developers meet with the source to ask questions and better understand the mission and goal of the project. Let the Operations crew have a peak at what's coming down the pike and get some requirements from them too.
Project Management and Prince 2
AC asked "May I ask what you dislike about prince2? Never used it, only heard of it recently."
Well, it's top heavy for most projects, it mandates too much paperwork (have a look at the templates at http://www.prince-officialsite.com/nmsruntime/saveasdialog.asp?lID=1284&sID=455) but not most of the paperwork that a proper software development project needs (that is OK if top management realises that it was not intended to tell you what domain-specific documentation you need, but top management types are often too thick to understand that), any project management method that requires 45 little processes grouped into 8 big processes and appears to have no dataflow from any other big process (not even the project startup process) into the planning process is obviously crazy, it tends to encourage senior management to think that they can know what products are required and what it will cost to develop them before any real design work or research has been done, it has "scalability" based on advice as to which bits of it are likely to be useful for your project but the advice is such that it often leads to what's known as PINO (Prince In Name Only) projects, and Prince 2 is the mechanism mandated by our government which has been used to manage every government IT catastrophe since 1996. But the best way to understand it is read the APM websites http://www.prince-officialsite.com/ and http://www.apmgroup.co.uk/PRINCE2/PRINCE2Home.asp and maybe the OMG prince website too, perhaps look at wikipedia first (note that I'm only suggesting that you look at websites written by Prince2 advocates) and then get trained on it - and I believe that after you have done that, if you are any good you will realise that this can't be the right way to manage a software development project.
Rule # 1 - What About...
"Enable your developers to work in a manner that makes them most productive."
Too many times in my career I have had to deal with managers who believe the only way to get work done is to do it the way they would. I don't just mean using the same methods, but the same work process habits. Some people can sit there for hours and crank out work continuously. Others work in "brilliant flashes followed by long blackouts." (that's a phrase one of my best managers used to use -- I loved working for him.)
A good manager will recognize the difference in how people work and enable them to work that way. If that means getting the employee access to the building from 7am to 9pm every day, so be it. If it means running interference when another employee says "He only put 4 hours of work in today, that's not fair!" so be it. Hours worked != work done.