Finding sources of information that are pertinent, relevant, of the correct quality is not always easy and displaying the resources you have studied in your work requires a high degree of formality.  All of this comes under the heading of ‘bibliography’ as you would both consult & develop bibliographies as you go about the task of research.

So…

Where to find relevant material.

1. Try to use google & its academic sub-division google scholar to search out material.  You will almost certainly have to then look in other places (such as libraries) for the actual material.
2. The University of California Press makes a lot of material available on line here (but it takes some digging through).  There are other online resources for books such as The Online Book Page.
3. Google Books might offer some relevant works.
4. The BL offers a search engine for its 19th Century British newspaper collection that could be incredibly useful (requires registration and sometimes a fee).
5. Jstor is the oldest & largest on-line repository of academic material and is free to search (but almost all material costs – often a lot).
6. The IHR offers a lot of material including its Reviews in History on-line journal all of which could be very useful as is its guide to online resources.
7. Open access repositories such as SAS Space may well offer very useful material.
8. The online versions of major journals such as History Workshop Journal can provide very useful guides to resources (such as this one)