Register a delegate on ARK mainnet. You can register a delegate within your ARK wallet.
We refresh a list of our delegates once per hour, so it can happen that you won't be able to immediately find your delegate, especially if registered it less than 1 hour ago.
Once you find your delegate (you can use the search form on the top of every page) click on it.
On your delegates page, you'll be able to find a big red box which indicates an account hasn't been claimed. Claim it by clicking on the "Claim this account" link. A form will open - follow the instructions on that page.
In case of any issues, please join ARK's Slack and ask in #delegates channel.