My take on things:
Profession (Journalist): You are able to market and sell stories, using this skill to make a living as a journalist. This includes things like making sure your expenses are properly covered, getting steady work, selling stories to news outlets, marketing yourself and your journalism to your employers and the like.
Hence this skill is used to determine how much money you can make as a journalist, earning 1/2 a check in GP per week doing so.
Craft (Journalism) : You know how to write a story, including basic research, presentation, keeping the reader's interest, showing relevance, imparting bias to suit your desires and such.
Knowledge (Journalism): You can name various relevant journalists of the past. You are able to single out very significant stories, both in how they affect journalism and how they affected the world at large.
There's a lot of potential synergy bonuses and secondary checks both skills if you want to reduce the level of abstraction. Trying to write an editorial? 5 ranks of diplomacy gives you a +2. Using an outright lie or an example of a faked document to slander someone? Bluff synergy or a forgery check (against a set DC depending on what you want to falsify, failure or success could be a big bonus or penalty to the craft roll, but in either case you'll most likely get a bonus to the profession roll if you're trying to sell the piece to a news outlet that likes that sort of thing and a penalty if you're dealing with one that would just see it as a waste of space).
From a standpoint of NPCs a journalist most likely has some other skills like sense motive, gather information, search (and maybe the research feat), diplomacy and whatnot.
Someone with a high craft but low profession would be a diamond in the rough. They would put together wonderful copy but few would be willing to pay a lot for it. They add have meaningful, insightful or worthwhile content to some otherwise crackpot newsletter that's little more than a platform for outrageous conspiracy theories and madmen.
Someone with a high profession but a low craft would keep having his stories appear in prominent, respectable publications, despite their content (or lack there of). They could simply be a shameless self-promoter with a lot of inside contacts who simply does 'fluff' pieces and makes a killing on them, or they could be lazy and quick to jump to conclusions, potentially causing major scandals when their research is debunked or proven biased, when their stories are shown to be falsified or simply making you wonder "Why do they put this junk on the front page" every now and then.
Now for a PC journalist, what they do in the process could be half the fun. Having them make checks to research (search), dig up info (gather information), let sort out follow false leads (sense motive), get more information out of an interview than the person is prepared to give (diplomacy). Then let them make a craft check against a DC determined on how hard it is to come up with a good story based on what they know and see (and how long it takes). Finally let the value of the piece to influence how much they can peddle it off to what people for. A series of good articles could give way to public demand for more pieces of the same type or by the same author which could affect the price of future work.
Or just let them make the craft check every night to see how far they get in working on their current piece (DC would depend on the quality of the article they were looking to write), then let them make the profession check every to see what they’re making(with a bonus or penalty depending on what they have to sell).
