How to set up a remote server to do delegate harvesting

I activated the option do delegated harvesting. Now I realise that I ofcourse need a remote server with oppropiate software installed to do delegated harvesting. Are there any instructions somewhere how to set such a server.

Do you know bout any good cheap VPS-service that could host remote harvesting?

If I have activated the option delegated harvesting, how can I then do local harvesting? I see no button to click or anything similar.