I am a high school teacher in Texas. I am in my seventh year of teaching. I teach physics, which means I have pretty good students overall, so keep that in mind.
I absolutely love being a teacher! I can’t imagine doing anything else. I was a very “high achiever” in high school–1st in my class and all that. It’s hard for a lot of my friends and family and even my students to understand why I’m a teacher and not doing something “more important.” I’m never sure how to answer that, because if they don’t already understand that the education of our young people is one of the most important things in the world, then there is no easy answer. But I always try. 
At the end of my first year of teaching, I absolutely hated it and thought I had made a huge mistake! By the end of my second year, I was falling in love with teaching and I knew that I had made the right choice. Now I am in my seventh year and I find that the reason I really love it is that there are always new challenges and there are always ways that I can improve myself and my teaching. I don’t let it become “old” or “routine” to me.
It IS a LOT of WORK! My “official, required hours” are from 7:00 am to 3:00 pm. I rarely ever go home before 4:30, and then I have papers to grade and lessons to plan at home. I am also a sponsor for a couple of student groups, so I usually spend one or two evenings per week at the school.
As for summer breaks, we have a two month summer break and several short breaks during the school year. This differs by school district.
As far as salary: Often the lowest-paying teaching jobs are the ones at the nice schools in the affluent suburban areas. These schools are more attractive to most applicants because they tend to have fewer problems (lack of motivation, crime, overcrowding, poor facilities) than urban schools. These affluent schools can offer lower salaries and easily find teachers because they are “better” places to teach.
BTW, I teach in a middle-class suburban area. I do not have a family to support (yet), so money has not been a huge concern for me. Someday that might change. I don’t bitch and moan about making a low salary (for a college-educated professional) because I knew about that before I got into teaching.
[soapbox] HOWEVER, I do find it very perplexing that society pays us so little for the important job of educating their children. Paying higher salaries would attract more people to teaching, which would make finding a job more competitive, which should put more qualified and talented people in teaching positions. I would welcome closer scrutiny of my job performance if it means an increase in the quality of education (and of teacher salaries). Screw those teachers unions that are opposed to holding us teachers accountable for how well we do our jobs! I know that I am a good teacher, so those things do not scare me. Bring it on, please! It’s time to get rid of those teachers that “mail it in.” It’s time we stop paying coaches extra stipends to do less teaching. The golf coach at my school teaches two classes and then leaves at 10:30 to play golf the rest of the day! Really! And for this he gets paid a full teacher’s salary PLUS an extra few thousand dollars stipend for “coaching” (which I’m told he does very little of). Oh, and many of the golf tournaments are scheduled during school days, so he often has to have a substitute teacher (more money down the drain) and his students have to try and teach themselves. Is this how our tax dollars are best spent? I’m not even a parent, but THESE ARE OUR KIDS, for Pete’s sake! Don’t they deserve the best? [/soapbox]
Arcite, if you like kids and you have a positive attitude and a good sense of humor, and if you’re something of an idealist (like me), then teaching can be a wonderful thing. It has changed my life–I have grown so much as an individual because of my experiences as a teacher. But it isn’t something to be entered into lightly. Getting the required college hours in education and in the subject area you want to teach (if other than your degree) will take a commitment of time and money. And being a teacher is a huge responsibility. You have the opportunity to shape the future of your students. Reminds me of something my uncle once said to me, just before he died… “With great power, comes great responsibility.” Oops! I’ve said too much… 
Good luck!