One aspect of website translation that is very often overlooked is that having your website available in more than one language means that it can be indexed and searched by the major search engines in other languages, as well as just the main language that your website is in.
It is well worth considering what languages your main customers may speak and what other countries you may want to attract and tailoring your site to this. Having your website indexed on the major search engines of other countries will automatically increase your exposure to new visitors in a major way.
Having said this, when somebody from another country does land on your site has had a hit from say, Google Germany, they may leave straight away when they find no content in German. This is where you may want to consider having a US English to German translation of the relevant site contents as well as just the search engine attractors.
Even if you do not want to translate the whole website into various other languages, it is certainly worth considering providing keywords in different languages on each of the major searchable pages and at least getting a website translation agency to look at your site and give you an idea of how much would be involved in doing translations of various parts of your sites, such as summaries, technical information and of course, sales information. This is a cheap and easy way to open up your site to the world, or at least more of it than would be so if your site is just in American English.
