What to do when students bring me questions related to other courses and subjects? I teach all of the writing courses for one of my college's STEM department. Occasionally, students bring me questions related to their field, e.g. they are doing some project for another course and they want to know what tools I used for a similar real-world project I did before.


If I help the students (which would amount to suggesting some books, tools, Web sites), perhaps the department will feel I am interfering in matters where I should not, as this is not my teaching area.
If I turn away the students, perhaps the department or (students themselves) will feel I am not committed to serving the students.


What is the accepted procedure for such a situation?
There's no shame in saying you're not an expert in their domain specific knowledge.  It's more important to know your limitations than to give advice you're not directly qualified to give.  Direct them to a professor in that specific field.  

If you feel you have sufficient experience to give (at least) a starting point, by all means share it with them.  Just always make sure that you are clear about the limitations of your expertise.