"You don't need to understand it--just translate it!" A typical response to a well-meaning translator from an exasperated client confronted with a long list of queries on the text for translation.
Thankfully, such blinkered clients are the exception. But the underlying issue is important: The "translator of words" is permanently at risk of producing a finished text firmly in the tradition of those notorious instructions for Japanese household appliances. Translation--or technical translation, at least--is all about meaning. It requires an adequate grasp of the source text (plus associated conceptual framework) and the ability to render this coherently, using a suitable style and the correct terminology, in the target language, which should normally be the translator's mother tongue.
Not all these skills come naturally to a modern languages graduate, and, although a language degree might be the traditional launching pad for a career in translation, many do move, or drift, into the profession from other directions. Mine, admittedly, was a conventional route, although I did not have my sights fixed on translation from the start. After gaining a degree in French and German in the United Kingdom, I put in a brief spell as a computer programmer in London and taught English as a foreign language at night school in Germany for a good 6 years, before finally becoming a full-time translator in 1990.
Of course, it pays to be in the right place at the right time. Through a quantity surveyor friend, I started translating technical texts from German into English for a Zurich-based company that produces standard specifications and cost-control tools for the Swiss construction industry. 1990 marked both the beginning of an intensive 7-year collaboration and, for me as a linguist knowing little about the building trade, a genuine apprenticeship during which I set about bridging the knowledge gap.
The fields of architecture, construction, and, more recently, real estate have now become my niche. I work partly as a "lone ranger" with my own modest stock of direct clients (e.g., construction product manufacturers) and partly in collaboration with a Swiss-based translation agency.
Although in Germany, at least, there are no statutory restrictions on the use of the title "translator," it obviously helps in procuring work if you belong to a professional association,* membership of which is subject to fairly stringent requirements (formal training and qualifications, working experience, etc.). Indeed, the importance of a close familiarity with the foreign language should not be underestimated. After all, it's said that it takes a lifetime to learn your mother tongue, and the proficiency in a foreign language necessary for doing any type of translation work undoubtedly requires an extended period of study and contact with the language, preferably in the relevant country.
Working from home as a freelancer gives you considerable freedom, notably in terms of working hours. Although discipline is paramount, different routines are possible: You may prefer an early start and an early finish, but there is nothing (and nobody) to stop you from browsing through your newspaper over a hearty brunch provided you do not mind putting in the evening shifts. ("Extreme" translators are those who work through the night and deliver their translations on a just-in-time basis.) Many translators complain about tight deadlines, and it is certainly true that you have to consider carefully what you accept and what is best turned down. Although holiday periods, e.g., summer and Christmas, tend to be less stressful, weekends require careful management, as clients commonly favour late Friday afternoon to off-load jobs they need back Monday morning.
The geographical freedom offered by the Internet also allows those who so desire to migrate to warmer climes while remaining only an e-mail away: Work can now be clicked to and fro across the globe. (I can still remember the messy days of mailed diskettes!)
In terms of IT, I find it vital to keep pace with hardware and software developments to ensure compatibility with clients' applications. Although there are various translation-support programs on the market (which, among other things, tell you if and how you have translated an identical or similar sentence in the past), they are not as yet an absolute must. I personally make do with a terminology-management program. I also use a voice-recognition system to dictate translations, which bumps up my output appreciably.
Other key resources include translation dictionaries, although their quality and usefulness vary dramatically. As I see it, the specialist dictionaries of the future are likely to transcend the conventional A-Z arrangement and focus more closely on presenting structured knowledge, around which terms, definitions, and their translations are arranged. Dictionaries of this kind will inevitably be produced by people with the relevant scientific and technical backgrounds.
I myself tend to make much greater use of single-language dictionaries, glossaries, and manuals. The Internet too is an invaluable resource, providing both limitless information on any conceivable subject area and an efficient method of validating terminology.
Of course, in an ideal world, the client would be a further resource. However, without wishing to be overcritical, it must be said that the (technical) author of the source text--through ambiguity, semantic shortcuts, inscrutable abbreviations, and nonsystematic use of terminology, to name just a few typical foibles--often contributes to the translation problem. Moreover, apart from the knowledge gap, there is also an information gap: Project documents, for instance, are rarely self-contained entities, and a modicum of background information on the relevant project often helps significantly in interpreting otherwise cryptic references.
Which again underlines why an active partnership between client and translator is so crucial--and brings us back to that frustrated, conscientious translator with his query list, pondering how to bridge those gaps in his text. No simple answer, I'm afraid. Understanding technical details can be a long, hard slog for those who are unprepared and/or left in the lurch. Who said translation was easy, anyway?
* The Bundesverband der Dolmetscher und Übersetzer e.V.  is Germany's largest association for translators and interpreters.