As of Monday May 5, 2014 the USCIS will only accept the new Form N-400, Application for Naturalization, which is dated 9/13/13 and expires 9/30/15. Any other version of the form will be rejected by the USCIS. The new form has new or additional questions about security-related matters, whether the applicant may have persecuted others, and more. A barcode across the bottom tracks the information that is typed into the interactive PDF. Applicants also still have the option to apply by hand.
Here is a list of resources on the new N-400:
The CitizenshipWorks website offers an interactive interview on naturalization eligibility; a self-paced interactive tutorial that explains the process step-by-step; a tutorial to prepare for the tests; and links to other resources and information in English, Spanish, Chinese, and Vietnamese at www.citizenshipworks.org.
Immigrant Legal Resource Center (ILRC)
The ILRC provides the new Form N-400 translated into Spanish, Chinese and Vietnamese at http://www.ilrc.org/resources/n-400-translations-in-spanish-vietnamese-chinese.
New Americans Campaign
The New Americans Campaign is a national network of legal-service providers, faith-based organizations, businesses, foundations and community leaders that is paving a better road to citizenship by modernizing and streamlining access to naturalization services so that greater numbers of legally qualified permanent residents take the critical step to becoming U.S. citizens at http://newamericanscampaign.org/.
U.S. Citizenship and Immigration Services (USCIS)
The USCIS webpage with the new Form N-400 and additional information is available at http://www.uscis.gov/n-400.
Please keep in mind if you have a past which may jeopardize your immigration status, such as past fraudulent applications or past criminal history, it is best to consult with an attorney to verify you qualify for Citizenship. Most of the organizations do a great job in screening for problems and if they believe you may have a problem, they then will recommend you seek a second opinion. Nevertheless, you are ultimately responsible for making sure you have disclosed all of the pertinent information to verify you qualify for Naturalization.