A small start would be fixing up the Wikipedia article: Government procurement in the United States.
A concerned citizen or civil servant not currently involved in procurement reform needs a basic overview of the current situation to figure things out.
Basic information for beginners would be something along these lines: USG purchasing in 2013 was estimated at roughly this level. The laws governing this process are ... ; the principles in these laws are ... ; major differences between public sector and private sector purchasing are ... ; the people and organizations who conduct procurement activities are called ... ; the typical steps in the procurement process are ... ; plus a few paragraphs giving examples about how procurement works in different agencies. For more information, see the article "Request for proposal," etc.... ; This information is taken from the following sources ... ; see these helpful links and overviews for futher information.
Happy to assist anyone willing to attempt this rewrite, if you e-mail me. (I know very little about procurement, but do know about editing Wikipedia.)