Acronyms: In general, spell out word phrases that use initials the first time, then give the acronym in parenthesis. After that, use just the acronym without periods. For example: Physical Education Instructional Facility (PEIF).
If you are still in doubt, spell the word out.
Ampersand: Don't use the ampersand (&) in body copy. It should be used only in corporate titles when that is their style.
Course titles: Use a two-letter abbreviation with no periods as in EN 111.
NMU: Capitalize. No periods. However, it is a good idea to write out Northern Michigan University the first time in an article; use NMU or Northern in subsequent references.
Two-letter and three-letter abbreviations: Other two-letter abbreviations are used with periods, as in a.m., (note lower case), R.N., U.P. For three or more letters, do not use periods as in WNMU-TV, GPA, NMU.