These are things I have used and will continue to use. I found them on Pinterest (clearly), so the links will take you to the pins.
This list of Beginning of the Year Procedures, so you don't forget to go over something. Checklists are great for that first week.
This Non-Fiction Notes strategy. I don't have it made into an anchor chart, but I have it on a piece of paper I project and the students copy it down. I should make it into a form for this coming year...
I use it for articles, partner-reading, and videos. You can give any video a purpose by making them accountable for completing this task at the end. Sometimes BrainPop can just explain it better than I can, you know?
What Does My Grade Mean? I've made this into a handout for parents and students and also have one to project on the board as I hand back tests. Kids always want As (uh, so do the parents) but sometimes they (students and parents) don't get that a B or C is fine, because learning is the goal. Anyway, we still do letter grades in 4th and 5th grade in my district but it's a jump from the standards-based grades that they are used to in the primary grades. This is a handy explanation.
I love this colorful bulletin board display. It's perfect for hanging work and anchor charts and easy to change things out often. I would HIGHLY recommend making one if you have the wall space. The picture of mine is in the graphic at the top of the post.
For Open House/Meet the Teacher Night, I used cardboard boxes with labels to have the kids sort their own supplies. It was amazing. Here's a picture of mine.
I used this substitute form when I taught 2nd grade. Currently, my district provides one for the sub so I don't make them fill out two.
I did this highlighter trick next to the turn-in box. It worked two years ago, and didn't work well with this last group I had. I'll probably try it again this coming year.
I did this math trick with 4th graders. It works well with inquisitive kids.
And Flocabulary has some very engaging songs/videos for older kids. I did not find this on Pinterest, but I pinned it.