Just go to marketplace.sitecore.net/Contribute.aspx
and fill in everything.
After you complete everything you can submit it for review, this can take some time, from 1 up to 3 weeks.
note: there are some issue with browsers if you have issue try another browser,
pro tip: Things are stored in a folder structure a/b/c e.t.c, there are lot of modules starting with s, start with a different letter gives you a perhaps a faster experience?
See also sitecore.stackexchange.com/.../4474