The application page for wave 2 isn't up yet, as it seems.
People are releasing their maps to the public by uploading them to any hoster (Filefront.com, RapidShare.com, Mediafire.com) and then posting the download-link in a release thread in either the Beta or the Final section, depending on the state of the map.
Pack your map and all additional files you want to pass on along with it (e.g. the readme-file or any packages that are needed to run the map and don't come with the game) into an archive like .rar, .zip or .7z. Use Winrar from winrar.com or 7-zip from 7-zip.org to do that.
You should also post a description of your map so people know what to expect. Most people also post some screenshots. You do that by uploading the screenshots to an image-hoster (imageshack.us, photobucket.com) and posting the "direct link" to the image(s) into an image-tag. Type it like this:
Code:
[img]http://www.directlinktoyourimage.com[img]
Check out some other release threads to get a general idea of what is expected.
When the application page for wave 2 is up you can go there and you'll be guided through a bunch of self-explanatory forms and you get to upload screenshots and the map-file there again and you won't need any other external hosters. In wave 1 it was all pretty self-explanatory and I assume it's going to look very similar in wave 2.
Good luck, man! Not just for your release thread but also and especially for the contest! I'm looking forward to seeing your map!