Rule 2. Two singular subjects connected by or, either/or, or neither/nor require a singular verb.
Rule 1. A subject will come before a phrase beginning with of. This is a key rule for understanding subjects. The word of is the culprit in many, perhaps most, subject-verb mistakes.

Rule 3. The verb in an or, either/or, or neither/nor sentence agrees with the noun or pronoun closest to it.
Rule 4. As a general rule, use a plural verb with two or more subjects when they are connected by and.
Rule 5a. Sometimes the subject is separated from the verb by such words as along with, as well as, besides, not, etc. These words and phrases are not part of the subject. Ignore them and use a singular verb when the subject is singular.
Rule 5b. Parentheses are not part of the subject.