International parcel shipping to the Ukraine

Good morning. I am with Branch Banking Systems Corp and we specialize in banking software for security purposes. I have an immediate opening for an International shipping company that I need to fill. We have parcels that we need to ship to some clients in the Ukraine, both in Donetsk and in Kiev. I will be needing to ship these parcels starting at the beginning of next month but they will be ongoing as this is an legacy client in the Ukraine so our business relationship is fairly far reaching. I would like to know about the Customs process when shipping there though. I would like to know things like what sort of duty fees are we looking at to ship these parcels and what sort of extra paperwork do I need to have affixed to them when I send them. If you have some sort of chart or reference guide in this light, that would be helpful.