Also a great resource for tips and tricks is ammo NYC. The guy makes great videos and has product to sell, but doesn't crap on other manufacturers products. It's mostly about technique. The biggest take away is to touch the paint as little as possible and keep it lubricated as you wash. You want to keep from introducing scratches. The metallic black should be more forgiving than a piano black.
You can check out autogeek as well for different products and reviews.
When I had a piano black caddy, I would use the two bucket, only touchless car washes during winter and I'd use a sprayer with distilled water to do a final rinse of it was mid summer to avoid water spots. It all helped, and it stayed pretty decent in the 5 years I had it, but after getting better with the polishes and waxes, I don't stress anymore. Regular car washes in the winter and once or twice a year I give it a full detail. The polishes work wonders and short of real deep scratches, it will get the paint back to near perfect. I figure it's more damaging to leave road salt and debris on my cars in the winter, than it is to be picky about washing during the winter months. Don't stress too much about it. Normally it'll buff out.