Just having found a temp assignment... you´re limiting yourself too much with segundamano. As most of the jobs end up being sales or such jobs. Sign up at temp agencies, just to name a couple: Ranstad, Michael Page, Adecco, I have more, but I´d have to check the names and post them another day. Also, el pais, use Infojobs.com- I´ve gotten a few calls from them
monster.es is another... and I even researched companies that interested me and went in person to drop off a CV. Keep in mind that here most of the time from when you start an intense work search from when you turn in a CV the avg is about 5 weeks to start having some news. Good luck!