Office hours are very scary places, the professors torture you and the proceed to eat bits of you. [/sarcasm] Just kidding, office hours are great, I would highly suggest you go often, it is one of the easiest ways to get to know a professor and to network. Try to do the problem sets, readings, assignments, etc. before you go in, so you have an idea of what you are doing, and ask a few specific questions that show that you are not just there to get a recap of the lecture. Office hours are times to make great impressions on professors, and with a great impression you can get great letters of recs, and research positions, and many other things; people don't like mentioning it but professors do play favorites if you land on that borderline between an A/B and the professors knows the the chances of them bumping you up go up exponentially.

Basic Office Hours Rules

• Ask specific pointed questions, they are there to answer specific questions, not to give you another lecture, show that you have made the effort to at least try ahead of time.
• Don't be the guy that hogs the whole hour, ask a few questions and leave if there is people waiting, if you need to have a longer discussion ask the professor to schedule an appointment, you share those office hours with your classmates.
• Don't suck up or brown nose, professors are really good at seeing through that, office hours won't get you an A or anything, but they can make you stand out and look like an exceptional student.

Other than that be polite, and good luck. From your previous posts; I take it that you are going to start college in the fall, just calm down, relax, enjoy your last semester as a high schooler, enjoy the summer with your friends, and just take it one step at a time. You will have a blast in college. It looks a little intimidating but, you will get used to it pretty quick.

Believe it or not, professors want you to come to their office hours. They are required to have office hours by university rules and are there specifically so their students can come in and ask questions, get short tutoring sessions, or just sit down and shoot the sh*t. The majority of professors I had in my undergrad I now talk to on a first name basis because I'd basically hang out with them and got to know them during their office hours.

What to expect...

• If you have questions, just have them ready to ask. Most of the time, conversation will follow, but almost always profs have lots of work to do too. Just use common sense - if they are talkative and want to continue talking, do so. Otherwise, excuse yourself in due time.
• Visiting a prof during office hours will let them learn who you are. They can get to know you on a more personal level. They will know your face, your name, and maybe a little bit of your personality (big advantage at large universities or large lecture classes). Having a more personal relationship with your prof may help when it comes to test time and final grades time too. They may have a little more leniency with you if they know you're going through personal situations, etc.
• Don't be afraid to request an appointment with your profs if their office hours do not coincide with your schedule. Communication via email or phone may be effective but meeting face to face is just a completely different thing. If you need the face to face time, request an appointment. I have not had one prof turn it down yet.

Otherwise, as insanemo said, just relax and go into college with an open mind. You'll have a great time. College will be the time of your life. Good luck!

[I feel incredibly authoritative, considering I'm sitting in my own office during my own office hours to answer this question. Sure, it's a box with a door, but it's mine and I love it. :)]

It really depends on two things: who you're going to see and what type of person they are.

While it's assumed that you just mean professors, I would also like to throw in the fact that TA's and advisors (like me!) have hours too, and we need the love. Professors typically have their own office, where assistant and advisors share. This means hours make all the difference if you want to talk to your TA, because they're scheduled for a very specific time.

Professors are technically people too, and like people, professors are all different. When it comes to hours, some professors have strict time periods while others just hang and have a little more leeway when it comes to walk-in times.

One major point that I can't stress enough is, HAVE A PURPOSE. Why are you there? Some professors might like you to stop by, shoot the breeze, ping pong tourney... But most professors use this time to be productive. Also, would you want to be in line behind someone who didn't know why they were there? Yikes.

One thing even I noticed was how some people are ready to argue more than anything else. Why are you coming to see me if you are just going to correct me and argue with a point? [in my position, I don't even make the rules, so there's no point] Even if you are coming in to argue a test grade, be gracious and understanding. It's much easier to get what you want.

Lastly, be respectful! These professors are spending extra time for you. They want to be somewhere else, trust me. If you need to coordinate a meeting, act like they are doing a favor for you. Cause they are. Nobody likes a brown noser, but understand the relationship between student and professor.

To review:

• Know office hour times, it'll keep you on the good side.
• Have a purpose. Otherwise, what's the point?
• Be open-minded. You want to know what they have to say.
• Be respectful. They aren't doing this for their health.