If you start from a "Good" article on Wikipedia, that means it's been evaluated by Wikipedians to contain quality sources. Other articles, however, may require a more critical eye.
In any event, be careful to write your article with a neutral point of view, and to avoid original research. In other words, avoid making connections or conclusions in your writing that don't exist in the source article.
For more help on translating with a critical eye, check out the Evaluating Wikipedia brochure, or the "Evaluating Wikipedia" training module.