I'm not so sure this belongs here, but could someone tell me how to submit our games/demos onto the site here?
First you need some web space to upload your game. If you don't own a website, try this thread:
http://www.adventuregamestudio.co.uk/yabb/index.php?topic=22428.0
Then if your game is complete, post in the Completed Games forum about it, or if you have a demo, post in the Games In Production forum.