How would you references your sources differently from an online library verses a traditional library?

Answer 1

It depends on what type of material you were looking at. A journal? An e-book? Information on a website?

Answer 2

first of all, you'll have to check that it actually IS a reputable library. Generally your schools intranet/library will give you links for recommended libraries

you put the normal referencing and then where u accessed it and when. So it'd look something like this (I think this is the Harvard style of referencing, check the style used in ur subject area!)
Lastname.J, 2006, Introduction to referencing. 2nd ed. Books&That, London, UK. E-resource: [www.thisiswhereigotitfrom/book.html], accessed 03rd November 2006

Formatting where required.

Your library should have referencing guides, which should include electronic resources as well!