Now my answer is by no means the gospel on getting indexed by search engines. But as far as I understand once you have created and published your hub search engine indexing happens quiet automatically. For example I have a hub that is about prayer. So each time a person does a search for prayer or related terms the search engine craws and indexes all relevant websites, webpages and even hubs that are about that subject. Once a person scrolls down to your hub in the search engine results the indexing or craw turns into a hit or a page view.
As far as getting indexed goes you do not actually have to do anything other then publish your hub for it to be indexed by search engines. Of course if you market your hubs on facebook or twitter and get traffic to your hubs via facebook this will help indexing and drive your page rank upwards in the page results. I hope this answer helps.