Hi
I've previously posted on this site saying that I am involved in software development and that I have set up an internet service.  I have spent the past few months trying to get a company interested in my site - as I believe it will be of great use to them as a method of advertising (not simply by advertising on the site, but in using the underlying software that I have developed).
Anyway, I've managed to arrange a meeting with one large company and this will be going ahead next week.  I know the target market and I know the benefits to the company I am meeting with.
However, I am unsure as to how much information I need to go with in a first meeting about negotiating a deal.  I would say that it is still early stages of interest between my company and the big company but how likely am I to be quizzed about what I want from the joint venture.
Should I have numbers in my head already in case any offer is made, or is it ok to say that I was just wanting to talk things through to see if you are interested first and then will leave negotiations for a second meeting.  I dont want to come across as under-prepared but also do not want to be pushy. i.e. without a companies backing, my software is almost worthless, so i dont want to aim too high. 
As I've said, I want to demo the idea and discuss it further with them but is this ok for the first meeting - saying any other discussions for a future time.
Also, as the company I have targetted isnt a software company it could (could!!) result in them wanting me to work full time on this project and therefore quit my day job. Should I be prepared to offer this as an option to them at this time, or save it for some future meeting.
Any help on first meetings with prospective customers/partners would be greatly appreciated.