Architecture behind large-scale social sites like Twitter - help with a new startup.
I apologize in advance for this not being a specific programming question, but I believe this is the best place for such an inquiry.

Basically, I have an idea for what I believe to be an interesting social networking site (not just a clone of existing things, but something useful and unique); I have a detailed specification document describing how everything works, but I'm not sure how best to proceed from here.  Architecturally, it seems like it would be most similar to something like Twitter, and I have some idea of what technologies are involved in this (SQL database, ajax, mobile integration, etc.).  I do not have the time to code everything myself, and honestly some of it is likely beyond me.  So, I suppose my pool of questions is something like this:

Assume I am non-programmer with a legitimately good idea for a new and large-scale social networking service, similar (in architecture) to Twitter, and some capital to make it happen: 

How do I proceed?  
What is the architecture behind a site like Twitter and what technologies does it use?  How do I find people with experience building these types of systems for consulting/development purposes?  
Are there any initiatives (government or otherwise) that can help me in such a start-up endeavor?   

I appreciate any help you can offer.  Thanks, and again I apologize for the broadness of this question.
Architecture behind large-scale social sites like Twitter - help with a new startup.
===

I apologize in advance for this not being a specific programming question, but I believe this is the best place for such an inquiry.

Basically, I have an idea for what I believe to be an interesting social networking site (not just a clone of existing things, but something useful and unique); I have a detailed specification document describing how everything works, but I'm not sure how best to proceed from here.  Architecturally, it seems like it would be most similar to something like Twitter, and I have some idea of what technologies are involved in this (SQL database, ajax, mobile integration, etc.).  I do not have the time to code everything myself, and honestly some of it is likely beyond me.  So, I suppose my pool of questions is something like this:

Assume I am non-programmer with a legitimately good idea for a new and large-scale social networking service, similar (in architecture) to Twitter, and some capital to make it happen: 

How do I proceed?  
What is the architecture behind a site like Twitter and what technologies does it use?  How do I find people with experience building these types of systems for consulting/development purposes?  
Are there any initiatives (government or otherwise) that can help me in such a start-up endeavor?   

I appreciate any help you can offer.  Thanks, and again I apologize for the broadness of this question.