Sign languags are a group of languages in the same way that spoken languages are a group. Each language is a distinct language with its own grammar and vocabulary, there are over a hundred sign languages and typically only half of the people speaking a sign language are deaf.
Many sign languages received an official status in the last fourty to fifty years and from that time many have been adopted in education and in some countries news programs have added an interpreting service in sign language.
As the basis of sign languages is based in movements and not in sound, the familiar writing systems are not applicable to them. In language research there have been several attempts to come up with a way to annotate sign languages and these did not lead to a writing system that was useful in day to day writing. The SignWriting script, developed by Mrs Valerie Sutton, however has been developed in over thirty years into a script that can be used for writing any sign language.
SignWriting is being adopted in education and, research has shown that the general rule that kids who learn to read and write in their mother tongue benefit for the rest of their academic career equally applies to sign languages. This adoption of sign languages is taking place but the one big hurdle is that there are so many sign languages and they all have no material to start with. The biggest technical hurdle is that while SignWriting is recognised as a script, there is no Unicode support for it.
At this stage most of the translations done into or from sign languages is one of interpreting or the real time translation of a conversation. There are people who have started to translate the bible into ASL or the American sign language and this effectively is one of the best signs of sign languages as a language that is being written.