Good luck this year! Sixth grade is a lot of fun to teach! I have a similar background that you do. I taught middle school math and switched down to sixth grade last year, but I also had experience teaching grades lower than that. You'll be fine!
Your idea of switching subjects every hour is a good approach. I pretty much structure my sixth grade class as an upper elementary class but challenge them as middle schoolers. I use the "Card System" where they have a card pulled if they call out, do something inappropriate, etc. I also send home reports to their parents every Friday & have them signed and returned that Monday. If they get on "orange" any day of that week it gets written on their report. If they get pink, it's an immediate phone call home. I will literally pull that student into the hallway with my cell phone and call their parent on the spot. The kids know I will do it, sometimes you have to make an example out of a student. Once they know you will do it, they know you mean business and will not mess around. My students get panicky if they are on yellow because they know. Just make sure you keep those phone numbers in your cell phone of kids that you most likely will need to call.
I also used the fingers for signs to get things. 1 finger meant they needed to sharpen their pencil, 2 fingers meant they needed to get something in the room (tissues, etc.), 3 fingers meant bathroom, 4 fingers meant water, and a whole hand is a question. It's a great system because you can wave a student to go do what they need to do without stopping instruction. I highly recommend this.
Even though it's sixth grade I have the kids line up quietly and I have them walk in the hallways in a straight line quietly. I carry paper and pencil and if they act out in the halls, it's a card & I write it down so I don't forget.
I also have classroom jobs and switch them weekly. The kids love responsibility and look forward to getting particular classroom jobs.
My sixth graders took notes, but I did not give them the same amount of notes that I had given my 8th graders. I tried to keep things lighter, game oriented, and more hands on. Last year my sixth graders told me that they loved their classroom and how it was decorated. They loved all the colors on the wall, their work everywhere, the bulletin boards, decoration, and they took pride in keeping it neat. Sixth graders are still very young kids and don't mind being in a comfortable room that is decorated "cute". However, the work load obviously does need to be heavier to get them ready.
A good "break" for the kids is reading time, art, or crafts. If you have a computer lab, projectors, etc. Have the kids create their own PowerPoint Presentations and give a speech to the class on a relevant topic. My kids LOVED doing this. They also LOVED writing plays & acting them out. But every class is a little different. My advice is to decorate the classroom in sections, have a math, science, english, and social studies corner. Hang posters & info. in that area and leave room to hang up student work. I found a U shape works best. Groups talk a little too much, rows are too old school, and U's are a great balance of it all.
Sixth graders love games, so if you can make anything into a game they will be happy. I played a game called "Snake" with spelling which they loved. After they had their spelling words for a day or two, I'd have them all sit on their desks (which they loved). I would go around and give a spelling bee. If they got it wrong they would sit down. The last one sitting on their desk wins. I have a projector so I like to make any chapter in a textbook to be a "Who wants to be a millionaire" or "Jeopardy" game on the computer. If you have projectors at your school (or want to front money to buy one), your students will learn & have so much fun. Check out this site: http://teach.fcps.net/trt10/PowerPoint.htm
They also loved "Silent Ball" when we had like 15 minutes extra at the end of the day after clean up. They would, again, all sit on their desk. They couldn't talk or they would be out. Students would pass a soft ball to each other around the room and if they missed or passed it back to who gave it to them, they were out.
They also don't mind being a little babied at this age, which is why they are okay with a comfortable, colorful classroom. I hope you have a great year & I hope this helped a little!