When you submit a website here it crawls the URL and adds the title, description and keywords from the metatags in your header (if any) to a 𝓆ueue. If/when the admin approves of the site you submitted and find's the content "of said site" to be non offensive, it will be approved and available to search in the database.
With that being said, if you have (or know) of a website worth contributing then by all means use the form on the home page and crawl it. Once you've done that come back in a few days or so and perform a search on the domain or it's meta content. If it was approved it will show up in the search results. If it doesn't, more than likely it was either rejected or just not approved yet so you may want to give it a few more days and check again.
That's about it really and thanks for reading!