I recently came across a great document on the Navy Supply Systems Command (NAVSUP) website, full of tips that could be useful to any small business who wants to market to any federal agency.
Do your research; understand the market; learn what (and how) an agency buys before you market to them
Remember that your core capabilities are more important that your socio-economic status
Make sure you have a good one-page capability statement
Don’t assume you won’t qualify for a contract – ask questions, submit a quote