We reserved our place in August and started settling in in October (at 8 months). I think we were told about the first settling in session maybe a couple weeks before. Then we just booked the next one when we went each time (had about 4-5 settling in sessions before she stayed her first half day). I think they told us what to pack at settling in or just before when we booked it (obviously she only needed that for days she stayed, not the initial settling in sessions). So maybe at most a couple weeks before.
As for payment, we were told what the cost was when we signed the contract obviously (it's in the terms and conditions), but we got our first bill when they issued the invoices for the month we started. So we started the first week of November and invoice would have come maybe last week of October (including a couple of the settling in sessions where she stayed with them without us) and then all billable days the first month. Our invoices were payable first Friday of the month, so like a week or so later. They won't give you an invoice way in advance if you haven't started yet. You'll just get them when everyone else does.
