There are two billing methods available.
The more common Auto Pay that debits your payment method on the day the bill is generated and an "Invoice Billing" option (with a $5 per month charge) that follows a more traditional billing date/ due date cycle.
As to seeing your pending charges before the bill is generated you can log into your Dashboard and see accumulated charges. Your routine service charges are ... always the same unless you change plan levels.
You can find your pending charges under the "unbilled activity" link: