Who reads teaching evaluations? At the end of each semester, usually a month before final exams, my school (in the US) distributes teaching evaluations. What people will read these? Do people only see these after the final grades are posted?
While this may vary significantly from institution to institution, my understanding is that, in the US at least, evaluations are at least read by:


The instructor, who needs to get feedback on their teaching efficacy
Others in the department who are evaluating the instructor, e.g., as part of tenure and promotion review, as part of peer mentoring, as part of a departments' own ongoing self-management.


They may also end up being read by other administrators (internal or external, e.g., certification authorities) who are monitoring a department's teaching quality, and may be distributed to students to help them decide which classes to take.  In these latter cases, it is likely that a summary will be distributed rather than the raw evaluations.

Timing with respect to finals and grading varies.  In all cases, however, institutions tend to take pains to preserve student privacy so that unless somebody leaves a clearly identifying mark in the comments it should be unable to affect their grades either way.