If you know of a source for the part you can quickly add it by clicking "Supply Pricing" on the BOM drop down. If the part currently does not have any stock, but you know the lead time on its availability you can toggle the availability from "units" to "days".
2. If the part is not available in the CircuitHub database you can add it by clicking "Add part to library"
3. If you wish to supply parts yourself, click "Consign part" next to the part number you will be supplying. After placing your order you will be provided with a shipping address for the parts.