Here's the MagPi's Rob Zwetsloot explaining how to use the Voice kit. The vision kit is similar except it comes with a camera rather than a microphone.
The original versions came out last year, and the new updated versions (of both the Voice and Vision kits) now come with Raspberry Pi Zero WH's and SD cards all set up and ready to go.
You can see more details about the kits from Google here.
Makers on the other side of the pond can get kits from Target while those of us in the UK will have to wait a few more months.
