16 days and no reply...
Well first you need to learn HTML and CSS. After you've made a few web pages (don't have to be hosted just for practice) learn something like javascript and make small games like "click the button". When you've become decent with JS, start planning your little text game. Write out all the things you want your players to do, but keep them in the realm of reality. When all that's finished just start writing the code out and get some cool artwork and boom... expand... expand... expand... have a few meltdowns (mental and game wise) and you have a game... You can learn HTML, CSS, JavaScript, and more over at http://www.w3schools.com/ ... Good luck
-Grigor