Of all the things I have to do each day as a principal, my favorite "task" is getting into classrooms each day to see what students are learning. I actually don't see it as a "task" of something I "have to do," in fact I prefer it over all the other things that are on my necessary list of to-do's (like the stack of paperwork!) I am very passionate on this topic and believe it is every principal's responsibility to be in classrooms. While I could write an entire book on this topic (and hopefully will someday) this post will just be some simple tips to get started.
It is very common for a new administrator to follow an administrator that was not in classrooms, which can make it awkward for the teachers and students that are not used to this practice. Or maybe you as an administrator have never really been in classrooms and have decided that you are going to start. If you just enter the classroom without doing some initial introduction of this, you will likely end up disrupting a class. Either the teacher will stop the lesson to greet you and ask what you need or a student will announce to the teacher that you're there.
Before getting started, you will need to inform teachers of your purpose for being in classrooms. During my first year as an administrator, getting into classrooms helped me to get to know all of the students, know each of the teacher's instructional styles/strengths, better learn the curriculum for each grade level, and just have a pulse of what's happening in the building. (If you want to know more about what I do with walkthroughs now, you'll have to wait for the book!)
During the first week of every school year I go into each classroom and read students a story, practice their names (I love it when I get them all right during the first week!) and tell students that they will see me frequently throughout the year as I come into their classroom. I tell students that I am coming into the classroom to see what they are learning and how hard they're working. I tell them that I do not want them to stop what they're doing and they don't even have to say hello to me when I come in. In fact, I tell them not to say hello, but if they must they can give a smile or a wave. I learned as an Instructional Coach that when the younger students wave they flail their arms around in excitement (which is so darn cute, but a disruption to learning), so I teach them instead to give a special little wave with just their index finger. This "micro-wave" is their special, silent way to say hello to me. When I go into classrooms, if a student shouts out or announces that I'm in the room, I treat it just as I would as a classroom teacher---I rehearse the procedure. I give a reminder that they can just wave, I walk out of the room, and then come back in so they can practice the wave. After 4 years of this, it is extremely easy to pop into classrooms and just blend into the room. In fact, a few weeks ago during summer school a student told his teacher that I'm like a Ninja, because I'm so sneaky!
If you're a new administrator or a veteran administrator, put walk-throughs on your daily schedule and get into classrooms!