SUB-Net is a part of the Small Business Administration web site on which large businesses, government agencies, and other prime contractors post solicitations and bid opportunities.
This is a good place for small businesses to search and view bid opportunities. Small businesses may also register in this area to post a bid opportunity, but only if they are seeking teaming partners or subcontractors for a specific procurement that they would not be able to perform alone.
To access SUB-Net, click on http://www.sba.gov/GC/indexcontacts-sbsd.html.
When searching, again remember to think like the government. Choose search terms that have to do with your end products, not your process.