Where to start?

[vcplz]

I say go to the wiki

http://wiki.frictionalgames.com/


and don't forget to look at the thread custom stories development with the sub forum development support

its gets easier after you've messed with it for a while
but you can upload it to any sharing site like megaupload, rapidshare, etc.

post a thread in custom story mods sub forum showcase
or ask let's play Amnesia youtubers to play it