Etymology of Spanish word "reloj"

Can anyone recommend a good web-based utility for looking up the etymology of Spanish words? And if it’s designed for English speakers, so much the better. I’m taking an introduction to Spanish course, so my grasp of the language is not good enough yet to navigate through a dictionary of Spanish for Spanish speakers. But having a couple of years of French and Latin behind me, and being a logophile, I’m very interested in etymologies. Is anyone aware of anything along these lines?

I mean we the most of mexicans. But I wouldn’t say it as a “hard g”. It’s more like a “soft g”, because trying to pronounce the spanish sound of the “j” at the end is a little uncomfortable.