Hi there
Yes they do have a job centre of sorts, its called the ETB. Bit like UK 20 years ago, they have a room with postcards with job details on however, in my experience most of them are out of date! I actually found employment through an agency located in 'Irish Town'. I went into their office and spoke with a guy called Ian, I think he was the owner. He was really honest and said that there was not much chance of me getting the employment I wanted (ie part time) but it was refreshing not to be strung along.
I received several job alerts and on the fourth one, I managed to get an interview and was employed immediately.
So, you might like to try the agencies, I know there are several but I actually only registered with 'Recruit Gibraltar'. Like I said I found it really great to have people being honest with me.
Good Luck
Jess