Conference papers are useful for finding very up to date information. New research might be presented at a conference before it is published in a traditional journal. In Engineering, for example, conference papers are a common dissemination method.
Conference Proceedings can be expensive, so the Library may not hold all the conference papers you need. You can use Inter Library Loans to request individual papers or whole proceedings.
Attending conferences in your subject field is a great way to build up contacts and start to network with other researchers. They are also useful to find out about new developments.Once you've started your research, presenting at conferences is a valuable way to publicly discuss and obtain feedback on your research.
AllConferences indexes upcoming conferences in all subjects
Conference Alerts indexes academic conferences
conference-service.com lists scientific conferences
Subject specific resources
Most subject specific databases index conferences; look for the option to limit your search by document type to conference papers. Some examples which include a lot of conference papers include:
ASME Digital Collection contains all the ASME Conference papers
IEEEXplore Indexes all conferences from the IEE and IEEE
Compendex A good source for all Engineering conferences
Web of Knowledge Includes the Conference Proceedings Citation Index- Science (1990-present)
Google Search by keyword and add the word 'conference' and the year to your search eg 'biology conference 2011'
Conference Papers Index
Available via the Proquest service, CPI provides an index to papers given at conferences from around the world. CPI dates from 1982 and covers engineering, physical, life and environmental sciences.
If your discipline is overseen by a learned society or a professional body (eg Law Society, BMA, RIBA) you will find links from their individual websites to conferences within the discipline.