the quickest way is to do it through chyoo.com. i think on there you can make your story locked so only you can add new choices and consequences. i'm not sure if they allow you to submit new interactive stories on literotica anymore - i remember when they removed a shit load quite a while back because people kept introducing underage characters.
You mean technically, or regarding structuring your work? I did this once about a year ago (a no-sex fantasy adventure), and my best friend became MS Visio, a program with a pretty good flowchart funtion.
Draw uo the whole thing on one of these with short content blurbs. Then start writing one path from beginning to end.
If you can, try to connect parrallell plots as often as you can. It saved a helluva lot of work. Computer adventure games work like that all the time, giving the reader an illusion of infinite choices and ends, when there really is one, or maybe a handful of ways to end the story.
If it's a technical system you are after, then I dunno. I did mine on paper.