I'm not sure if this is the right place to pose my question or not, as it is more of a general, 'how do I do...' than a specific political debating point. But I am hoping that there will be people with experience who will be able to guide me.
Following an email I cc'd my local MP on complaining about a specific area, he responded and suggested we meet to discuss it further. I now have a meeting with him this Friday afternoon and really I just would like some advice on how best to prepare. I don't want to be too specific about my cause, but it is something very close to my heart, something I feel passionate about and something I think needs changing fundamentally in this country - at central and local government and also across corporate Britain (so just a small thing then!).
I am pretty presentable and articulate, but what's my best strategy to get my MP on side and get him to support me in this? I am wondering what level of detail I really need to go to - just high level outline at this stage, or present him with some actual researched facts? How does lobbying really work? Realistically, what should my expectations be? What about Quangos? I have no idea how these really work and whether I should be asking him to make introductions for me?
Why do I always do this? Force my hand to make something happen and then panic?! 
Any help/advice you could give would be very much appreciated.