How do i start

OK! I'm sitting here thinking how do i start my client project i Thought of an idea and i know how i want this to be done but how do i create the environment..some times its so easy to put down your thoughts on piece of paper but it looks difficult once you start to work on them.i need to create a jail environment i have emailed the right people so now figures across God help me i hope i find what am looking for.