Here goes nothing!
1. Expect the unexpected! ~Those weekly lesson plans I worked so hard to type on Sunday afternoons never seemed to stay the same. Fire drills, Specials classes running over, vomiting students, substitutes, 2 hour delays, snow days, unexpected early dismissals, long assemblies....you name it, and it can happen and probably has already happened to some other teacher. I'd find myself constantly revising my plans on Thursday night so that they reflected what I truly taught, which just created more work for myself. I've since stopped that. Now I just delete what didn't happen, add it in to the next week etc, and note "SNOW DAY" etc.
2. Every day is a *brand* new day! ~ The great part about teaching in the primary grades, is that while students remember a lot, they won't remember everything. :) If you had a bad day and a lesson or two flopped, try again the next day. Half the time, since you're employing new strategies and activities the students don't realize the same concept is being taught again. Give yourself another chance! Give your class another chance! If one day, you left and had 5 kiddos on yellow and a couple on red, move 'em back to green and start a new slate on the next day. There's no reason to stew, just keep chuggin along!
3. Start a filing system~ BEFORE the year starts, decide how you will file tests, papers, units, etc. and what you will file. My first year I had parents sign and return every test, except spelling. So all of my weekly and unit Treasures test came right back to me. I made file folders for every week/unit so that I could reuse them. This past year, I realized I was a bit insane and decided that recording the grades was enough. But, for my Science and Social Studies units, I did something similar and made a file for EACH unit (or mini-unit really) and boy am I glad I did that. All of my units are in order from the first I teach in August till June, and I just grab em out and go. At one point I got really smart and started writing/inserting my lesson plans inside each folder. It's safe to say I'm SUPER GLAD I started this system my first year. I still benefit from it and it's saved me a lot of time. :)
4. Ask lots of questions~ So, I moved to a town I had never heard of or had ventured to when I started teaching about an hour west of home. I know, it's not that far, but I haven't always lived in PA! Anyways, the culture out by my new school is different-Pennsylvania Dutch and Amish. So at times, it felt like being in a different state. I had never heard of some foods and school traditions, etc. I felt silly about asking, but I had to. I'd be lying if I said I didn't receive some ridicule for it, but I'd rather not be ignorant lol.
5. Find one confidant~ You'll learn pretty quickly that teaching can often remind you of high school. Your main mission your first year is to find one confidant/expert teacher that you can trust. I was blessed to find mine super quickly and she had my back through thick and thin. Sadly, she retired but, I still call her for all kinds of advice and she still gives me old units, etc. I know I can tell or ask her anything without it ever traveling to another soul and that my friends, is priceless. You'll need to vent, you'll need to share your conquests and ideas, but make sure the person/people you're sharing with won't go sharing what you've said with the rest of your building, community, etc.
Hope that helps,