Well, I don´t think January is the best time to go, I´m afraid.
The language academies tend to be hiring up to September and very few teachers vacate their posts after one term. I took my CELTA in BCN in Nov 02 and looked for work for 4 months without success. There are a lot of foreigners there looking for that type of work (qualified and unqualified). If you can take your CELTA with International house, they have job opportunities advertised and they look favourably on their own graduates. They also run an introductory one week course to TEFL in their premises in Picadilly. However, it´s not cheap to train with them.
Accommodation is relatively expensive in BCN (for Spain) and there is a high demand for rentable places. The language academies have suggestions for places to stay for their students, so if you go through one of them, you might strike lucky.
There are a lot of things which you cannot really prepare someone for before they go to live in another country, and some things you are really better off finding out for yourself. If you can improve your Spanish before you go, all the better. Of course, they speak catalan there too!
Look at the web sites for teachers and read comments by teachers at daveseslcafe.com to get some more ideas.
I don´t wish to put you off, just to let you know that there will be a lot of people there competing for any posts that are available. So if you can study and perhaps do some voluntary work for your local authority teacxhing English to refugees before you go, you´ll have an edge.
Also consider brushing up your grammar (courses at the \"Citylit\" in London.
Good luck
