Are you applying for a design position on a magazine and the position requires only Photoshop knowledge?

The magazine will have it's own ways of doing things, they will have their own specification for photos/images. All to do with their presses and the paper the magazine is printed on.

I've worked on several different newspapers and magazines and also in an agency supplying hundreds of media; I needed to juggle lots of profiles and PDF output settings and proofing systems. So it's hard to answer your question, the company won't be looking for specific knowledge of their method of getting stuff press-ready. So all you can do is know how to adapt and show them that and know in general about supplying work for print. In which case these two places have quite good general guides for supplying artwork to print;

RCS; http://www.rcs.plc.uk/info/index.asp
and
Printing Dot Com; http://www.printing.com/knowhow

Also for an example one particular company; The Daily Telegraph newspaper and glossy magazine printing/press specs;
http://advertising.telegraph.co.uk/static/tech.aspx

Read it all, good luck with the job!