I need to have some supporting documents translated. How can I certify the translation is accurate?

Certified Translation requirements

"USCIS asks that you please submit certified translations for all foreign language documents. The translator must certify that s/he is competent to translate and that the translation is accurate. The certification format should include the certifier's name, signature, address, and date of certification. This generally goes at the end of the translated document. A suggested format by USCIS is as follows: ----- Certification by Translator I [typed name], certify that I am fluent (conversant) in the English and ___________ languages, and that the above/attached document is an accurate translation of the document attached entitled ______________________________. Signature: Date: Typed Name Address ---- CITATION: http://www.uscis.gov/forms/forms-and-fees/general-tips-assembling-applications-mailing"