The requirements cover a wide range of topics, including your supplier's top management commitment to quality, its customer focus, adequacy of its resources, employee competence, process management (for production, service delivery and relevant administrative and support processes), quality planning, product design, review of incoming orders, purchasing, monitoring and measurement of its processes and products, calibration of measuring equipment, processes to resolve customer complaints, corrective/preventive actions and a requirement to drive continual improvement of the QMS. Last but not least, there is a requirement for your supplier to monitor customer perceptions about the quality of the goods and services it provides.
ISO 9001:2000 does not specify requirements for the goods or services you are purchasing. That is up to you to define, by making clear your own needs and expectations for the product. You might, for example, refer to product specifications, drawings, national or international product standards, supplier's catalogues or other documents as appropriate.