As for regular maintenance, I think it's less about product and more about process. If you've got soft paint, you'll need to be especially diligent about minimizing scratches. I've used wool mitts (both natural and
synthetic), microfiber-covered sponges... you name it. Of the current, readily-available products, I do like the microfiber-covered sponges. Just keep it clean, & watch the pressure. I think most readily available car wash detergents would suffice. Try to hose off as much of the dirt & debris as possible... and keep your wash mitt/sponge as clean as possible. I throw mine in the washing machine every so often. If you get tough stains/dirt/bird droppings/bugs/ whatever... try not to scrub too hard. If you've got a good layer of wax/sealant, it should come off easily. If it doesn't, soak a towel & place it over the area & let it set for a while... should loosen things up for easy removal. If that doesn't work, you can resort to various solvents/chemicals. If you're really into it, you can go to the two-bucket method... with grit guards in the bottom of them, (so that your wash mitt/sponge doesn't contact the dirt/debris that settles to the bottom of the bucket)... my sponge always floats, but whatever. Supposedly, you use one bucket with the car wash in it, the other is just water, & used to wring out & clean your mitt/sponge.
As for drying... once again, everyone has their own preferred technique. I always start with a California water blade to screed off most of the rinse water, then go over it with "The Absorber"... a
synthetic chamois. Don't know that I'd use it on soft paint, but two of my fleet have super-hard clearcoat, so no big deal. Some prefer a natural chamois. Some resort to using a leaf blower, then follow up with a waffle-weave microfiber and/or microfiber towels.
Between washes, I'll occasionally wipe down with a quick detailer & a microfiber... if it's just dusty. Otherwise, it's a full-on 2 hour wash job.
I hesitate to advise too much... everyone develops their own process, and has their own favorite products. Some want fast & easy, others want perfection. There are any number of detailing forums where you can discuss these things. Everyone has an opinion. You need to determine how much time & effort you want to put into vehicular maintenance. Find the products & processes that work for you! (and your vehicle)
warning... it can become an obsession. I used to routinely wash my car(s) at least once a week. But now that I have four in the fleet, I've had to adjust my expectations for what I'll get done. Garage queens definitely require much less maintenance.