Google Translate stands at the forefront of machine translation technology. It can translate Hindi along with dozens of other languages. However, translation is a notoriously difficult job. "Can one translate a culture, its world view, its metaphysics?" The U.S. Poet Laureate Charles Simic once asked. Despite the progress made, machine translation is still in its infancy. However, Google Translate is a useful tool for novice translators. In addition, Babylon and Babelfish also offer free machine translation, and it may be worth comparing them.
Every serious translator has to eventually go running to her dictionaries. In addition to Hindi, a Sanskrit dictionary is invaluable to those seeking to translate Hindi. There are many Hindi dictionaries available online, but Shabdakosh is more comprehensive than the others. Similarly, the famous 1899 Monier-Williams Sanskrit to English dictionary is still in print and also available online, courtesy of Cologne University in Germany. Monier-Williams dictionary is particularly helpful to those interested in etymology of Hindi words and to those engaged in literary translations.
Unlike a tome of printed pages, the advantage of mobile phone dictionaries and apps is that they are easier to carry, access and use. There are many Hindi dictionaries available for download on mobile phones and some phone manufacturers offer Hindi language packs for free download. Similarly, Hindi language apps are available for iphones and Android phones. Mobile dictionaries and apps is a quick way to find the meaning of a new Hindi word, especially if it is a common, everyday word.
If the translation task requires a high level of precision, it may be worthwhile to find someone whose native language is Hindi, or, for a translator whose native tongue is Hindi, to find a native speaker in the language she is translating into. Translators Café, a directory of translators and linguists, can connect those interested with translators working with Hindi. In addition, Hindilanguage.org also offers translation services geared to business clients.