Russell Allert said
4 months, 2 weeks ago: @ccateringc Well, you could always hire my services for both, Richard. 
Transitioning is always difficult. I would bet that most of those who like your Facebook page would not be on G+ so telling them about your new G+ page would do little (although I would still do it).
It is difficult to say what I would do until I had a good look at your business and pages, but the first thing to do is to build up your G+ page. You will need to get this going first and then start moving people over.
As for using FB as an email capture strategy. You simply set up an email subscription form on your Facebook page, using a company like ShortStack and then drive people to that page-app.
You can do this via promotions, organic traffic, ads or any other means you can think of. Just make sure you aren’t tricking people to signing up. Another way is to give something very cool away for free if someone signs up. Or offer a great discount, depending on your business.
Hope that helps.
Russ