HAVA
The Help America Vote Act (HAVA) was enacted in 2002 and provided funds for upgrading the electoral processes and equipment of the United States.  Voting jurisdictions conscientiously following the guidelines of HAVA for the upgrade process, but were not provided voting equipment solutions which provide fair, accurate and transparent elections.  Congress, recognizing the potential for errors and even malfeascence is providing additional legislative guidance and funding to upgrade the existing voting equipment so as to provide voter verified paper ballots.  The intention of the proposed legislation is to insure a paper record is available to all voters for the 2008 General election with all equipment updated for fully voter verified paper ballots by 2010.  Several documents are available for reference as listed below.

HAVA is available here

H.R.811 ‘‘Voter Confidence and Increased Accessibility Act of 2007’’, the Holt Bill
H.R. 811 is representative of legislature being proposed to fix the problems with the voting systems.  It has exited committee.  The Holt bill is available here.

    Several additional documents to provide further information on H.R. 811 are available H.R. 811 FAQ, H.R. 811 funding requirements, H.R. 811 implementation H.R. 811 principal changes.

2005 Voluntary Voting System Guidelines
National standards are established for voting machines by the United States Election Assistance Commission.  They are in two volumes.  The 2005 Voluntary Voting System Guidelines, Volume I is available here, and Volume II is available here

Voluntary Voting System Guidelines to the EAC - August 2007

The Election Assistance Commission has released for comments updated Voluntary Voting System Guidelines in August 2007.  These guidelines are very complete and have included many areas which were not covered in previous guidelines. The TruVote system implements a significant portion of these new guidelines but will be updated as the new guidelines receive final approval from the EAC.  The guidelines are available here.