BTG website has a list exchanges, pools, and wallets on the site "https://btcgpu.org", which you can currently now access after this morning DDoSing.
Yes they mining will commence on the 1st of November, to answer the questions with why
The team is mining a total of (0.476%) I believe it was, BTG, to later support funding for the team, and later development

you can find out more specifically about that on page 9? I think it is

https://btcgpu.org/wp-content/uploads/2017/10/BitcoinGold-Roadmap.pdf


I'm personally waiting for wallets to accept the snapshot from earlier and post the actually wallet in their services.
considering the snapshot happened hours ago, and still haven't seen any wallet accepting "BTG" as its own "format"