As a beginning teacher, receiving student evaluations from the previous semester is a nerve-wracking thing. When you're first starting out, you have very few ways to gauge your effectiveness, and that first set of evals is often (but not always) the first sign you have of whether or not you're bombing out. That's not to say it's a particularly accurate sign, but it's a sign no less.
Though some people posture, saying they don't care what their scores/comments are, I've found that to be universally untrue, at least of the graduate student teaching population. Still, there does come a point when you care less, which, in the world of uber fragile grad student egos, is a pretty good place to be. I think I've almost reached that point (almost), and along the way I've gathered a few lessons.
The number #1 lesson I've learned from student evals. is something I knew anyway: students care more about their grades than anything else. And, a corollary - they don't conceive of a "C" as average/satisfactory, even if you do. And even if you say this every. other. class. period. for. a. semester.
Caring about one's grade first and foremost isn't, in and of itself, a bad thing (to my mind), but it does explain why year after year, students gripe about how difficult the grading in my class is - even when I feel like their end-of-the-semester grades are decidedly inflated and not a true reflection of many students' work and abilities. (Though, it should be noted that their grades at the time of evals are almost always lower than they are at the end of the semester because things like participation, homework, and revisions - generally factored in only at the end of the semester - raise student grades a lot. And this is something you eventually learn to live with, even if you do so with a grimmace.)
True, my grade spread is typically lower than most other teachers' that I've talked to, but not by so much that it makes a shocking difference. It's simply a fact that all students want an A, most think they deserve at least a B, and only a couple will be satisfied with the C that they earn. If you're not willing to change your grading so that your class average is a B+ (I'm not), then the best thing to do is accept the fact that your students will think your grading is too difficult - and move on.
The #2 lesson I've learned from student evaluations is that after a while (a few semesters?), they start to look pretty much the same from year to year.
See #1 for an example of this.
Now, don't get me wrong - these evaluations can offer meanginful feedback that helps you adapt your teaching style, and I have found them useful over the past 6 years. And I certainly always emphasize their importance to my students. But by and large, the "kind" of teacher you will become is set after the first, I don't know, maybe two or three years of teaching. And after that, not a whole lot will change in how you do things (for better or worse), and, therefore, not a whole lot of going to change in how the students respond.
For example, if you're the kind of teacher who provides extensive feedback on essays, it's probably because you find that to be really important. This is unlikely to change from semester to semester (though I bet you'll scale back a teensy bit after a while :), and students are, by and large, unlikely to respond to it any differently from semester to semester. If, by contrast, you think that large amounts of teacher commentary on student writing stifles the student's individual writing process (or you don't want to spend the time writing such commentary), you're unlikely to start offering pages of feedback after five years in the classroom.
This is, of course, a generalization, and I'm sure many people have made huge changes in their teaching practice after 10 years in a classroom. I just haven't seen it, and I haven't experienced it in my own teaching. Maybe I'll say something different 4 years from now. Anyway, the point is, you're going to see a lot of comments and numbers on these evals that look, well, a lot like what you saw last semester (and the semester before that, etc.).
And, directly in contrast to #2, the #3 lesson I've learned is to never be surprised by any comment or score you receive.
An example: a few years ago, I got the best scores I've ever gotten from the worst class I've ever taught. They misbehaved, didn't do their work, never participated, could have cared less about our class, and generally made my life miserable for a semester. And they knew I felt that way. (B/c I more or less told them.) And yet, when I received my scores, I was floored by how high they were.
While it's tempting to say, "They probably just didn't care enough to put anything but the highest number," once you understand students in general (they always care enough to complain - from freshmen on up through doctoral students, myself included) and this class specifically, it becomes apparent that wasn't the case. The explanation? Who knows. Seriously, I have no idea. The only thing I've been able to think up is that they somehow managed to appreciate the fact that I struggled day in and day out to get them to learn/care/participate when day in and day out they showed me they weren't interested in doing so. Even this is probably wrong.
But it works the other way, too - sometimes you're blind-sided by a nasty comment or two or by a whole set of not-that-wonderful scores. Sometimes, it's impossible for you to imagine who in your class could have written such an undeserving criticism ("But we had such a great atmosphere!" you exclaim) or how half the class could possibly think your (fill in the blank with teaching quality) was "about the same as other classes."
The key is to take it in stride. Spend a few minutes pondering the evaluation "surprise," see if there's anything useful to be gleaned from it, and if there is, great, and if not, that's fine, too.
Basically, while they can be important/useful/helpful, don't give the evals you receive after any given 15- or 16-week period the power to make you feel like Professor Idiot - or like Queen Teacher of the World.