Printing is an integral part of the process. There are several things you should keep in mind if you don't have your printed leaflets before you make a quote. If you haven't printed and even designed your leaflets yet, you will need to allow additional time for this on top of your distribution booking.
Most probably you will be asked to deliver the leaflets 3 to 4 days before the actual distribution happens. That is because of organisational and logistics reasons, accuracy and success of the planned leaflet delivery.
All items will have to be boxed in even numbers so that the packages are no more than 10kg in weight. Boxes must be labelled according to specifications, and larger quantities need to be palletised. Your printer should be able to follow these instructions easily, and Logiforce also offers complete service including design and print of your leaflets, so you will not have to worry about any of those details if you choose these additional services by Logiforce.
In any case, knowing the above in advance will help with not feeling overwhelmed.
A good strategy is to prepare materials and artwork well ahead of all planned distributions for the quarter or for a whole campaign (that involves more than one weekly drop) and then have these printed or delivered as needed.
When distributing two or more variants of the same item (i.e. you have two locations, and the addresses on half of your items are for location one, and the other half has location 2 for address) you might need to send the artwork to your leaflet distributor in advance to ensure they are aware which version goes where and in case labelling is not done correctly by the printer.