Although the naturalization application seems pretty straightforward, it is strongly recommended to have an attorney, especially where there is a prior criminal record.
Your "A" number.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.
Generally an applicant is not required to sign each document added as an attachment to an application. If you add an extra page of explanation as an addendum to the application form, generally you sign and date that page.