Depends on your hosting company. Those with cpanel installed usually do it at the beginning of the month
Yep, it depends on the control panel being used. This is something you'll have to ask your host about.
We don't reset it at all... This keeps your site from just going off line when you need it most. If you consistently exceed your bw allotment in a given month, we simply suggest moving to a different plane to suit your growing needs. I've always hated going to a web site only to find that it is down because the site owner exceeded their daily and or monthly quota. If you depend on your site to be up, why take the chance.
They usually do it automatically. Cpanel does it i believe. But dont go for a host such as hostgator. They'll suspend your accuont if you even use 1% of your allowed bandwidth a single day and make up some stupid excuse as into why they did it.
I got a reseller account just recently. Unlimited everything for one price. And with 4 nameservers to make sure the sites are up 99.99% of the time. One day, I may sell hosting accounts.
well, i got a 4GB / 70GB reseller on a liquidweb server a month ago for real cheap and am quite satisfied.