Newbie Looking for Help with Linking Databases

[joe.botz]

I just got Filemaker Pro 11 Advanced for my business. I have created three Databases: Inventory, Contact Managemet, and Purchase Orders. I need my purchase orders to take from Inventory and update the stock level. I need the bill to (address, city etc etc) information to be chosen form my contact management list. Can someone help me provide step by step instructions for these tasks. I have seen other topics relating to the same thing but for some different uses and I know there are steps i am missing.

Step by step instructions would be very helpful.

Thank You