Cro, a lot will depend upon what your specific editorial duties entail.
For instance, will you be solely responsible for layout, formatting, typeset, etc? For your section only?
Will it include graphics and illustrations? Only text?
Will it be entirely a paper publication, partially electronic (as in will there by an accompanying or redacted electronic version), only an electronic version, et?
What are you hoping to achieve? How much space do you have to work with?
How much freedom do you have regarding submission selection?
Will their be space for advertising? How many issues are planned?
How many copies per run do you plan to produce?
How many can you reliably expect to sell? What would you like to see in profit, if that is possible?
Is this an expandable effort? Do you plan to make it professional, or is this a hobby-literary production?
What is your target audience and what would they like to read and/or see?
Is the effort theme-based, open, literary, popular, poetic, genre-based, a mixture of types?
My advice is to ask yourself questions regarding every aspect of the publication that you will directly or indirectly control, or at least influence, and then start establishing efficient and suitable answers for each question. This will give you a basis from which to proceed. Know exactly what your duties are (and what everyone else's duties are up-front), and I would not overlook studying models that you admire (other publications) to gain some idea of what is possible, and of what you might desire to produce. Of course funding will directly determine what is actually possible, but within that general framework you should be free to experiment and evolve.
Of course nothing beats real world experience, so you will improve as you gain familiarity with what is required from the position and the enterprise.
My best advice though is ask yourself pertinent questions regarding your project and then develop an operating (and advertising and marketing, if appropriate) plan. This will save you much by way of trial and error, and resources squandered.
Good luck and Godspeed.