"Selling cars is my job."
Translation:Vendre des voitures est mon métier.
From what I've gathered from related responses, "emploi" means something closer to "employment", so it's something you have, as opposed to something you do.
Par exemple: "J'ai un emploi au bureau. Au bureau, mon métier est (to do whatever people do in an office)"
If this is inaccurate, please correct me!
Present participles and gerunds are two different uses for the same construction (in English).
Oh, wait, are you asking if that can be done in French? It's a tricky question because what the French call le gérondif isn't really the same thing as what we call a gerund.
This might help: http://french.about.com/od/grammar/a/presentparticiple_2.htm
In this case I don't think it holds up, because you only sell the cars your company has to offer, not all the cars in the world. I also get the feeling that using le/la/les for generalities is something for starting a sentence, not after a verb (with weekdays like "on fridays" being "les vendredis" being an exception).
album de photos is a collection of things which forms a whole - like in english you wouldn't say album of the photos, but photo album, the photos modify the album. Also if it's a quantity, like bouteille d'eau, or beaucoup de ..., These features usually mean you say de rather than des - whereas that doesn't apply to 'vendre des voitures'.