Below is the general outline for the Library of Congress call numbers for browsing areas in English language and literature. Reference works can be found in the reference room, 1st floor of Mullen. General collection books can be found in the Mullen Library stacks.
PE - English Language (2 South Mullen)
PN - Literature, Literary History and Collections (2 South Mullen)
PR - English Literature (1A Center and 1A South Mullen)
PS - American Literature (1A Center Mullen)
PZ - Juvenile / Misc. Literature (1A Center Mullen)
Most of the material can be found in the PE, PN, PR, PS, and PZ call number ranges. For a detailed breakdown of each call number range, go to the Library of Congress classification outline.
Your best bet: check the WRLC Searchbox for monographs and journals that could be applicable to your topic. Check the CU’s e-journals for full text journal articles in print and online.