Here is a list of supplies I use most often and things I find to be very helpful. Some of you may be lucky and have a school with a teacher supply closet. I do not. So all of my supplies are purchased out of pocket.
Pens in colors other than blue and black... I find it these colors blend in with pencil and make it harder to grade. I really don't like to use red either... Pink, green, orange, etc. Those are fun. My students especially like it if they are scented or sparkly. Well, maybe not the boys.
Labels-I use them to label my kids' folders (science, reading, etc)
Notecards-I use them for lots of different activities. 3rd graders aren't very good at writing without lines, so make sure you get the lined kind.
Sidewalk chalk-we use these when we learn about the sun and sometimes to do our spelling tests outside
Jump ropes, bubbles, balls, etc-for kids to have for recess
A bell-to get their attention
Craft sticks and a jar-to write their names on to draw sticks (to pick next person to read, make teams, or to raffle off a cupcake
Change-to buy candybars kids sell or for the soda machine
Pencils, pencils, pencils. Kids NEVER have a pencil. Somehow they always lose their pencil. They'll have it and then two minutes later it's gone. I think there is a pencil fairy who steals my kids' pencils.
Dry erase markers-we still have chalkboards, but each of my students has his own small dry erase board. I have them bring in a pair of old socks in the beginning of the year to use as an eraser.
Post-its-I use these a ton! We do sorts with them, use them as bookmarks, use them for 1-2-3 Magic, etc.
Glue, scissors, crayons, markers, colored pencils-you will always have kids who don't have their supplies. Mine are out in the open and free for anyone to use. It's good to model sharing.
Stapler and lots of staples
Lined paper and notebooks
Folders (by Christmas you'll be replacing lots of folders) and three ring binders (I use them as "privacy binders" the students are free to take one if they feel they need privacy from their neighbor)
Chalkboard eraser (luckily my school does give out chalk)
Wet erase markers for overhead
Baby wipes, Kleenex, hand sanitizer, baggies in gallon and sandwich size (my kids bring this in)
Your own small laminator and laminating sheets (our school's laminator is always broken)
Books to read
Erasers-the regular kind-not the kind that go on the end of a pencil-those are terrible and never stay on
Supplemental workbooks (wait to buy these until you can see what areas need practice)
Deodorant, travel toothbrush/toothpaste, perfume, brush, hairtie, tylenol, pads/tampons, small contact solution and case-I keep this in my desk just in case
Bulletin board border
Stickers (scented are way cool) and stamps
Hole punch (both 3 hole and 1 hole)
Paper to write parents or students (they love getting letters from me)
Paperclips and binder clips (in all different sizes)
Journal for you to keep track of RtI (more to come on this later)
Bookmarks (ask you public library)
Sharpener (the electric kind rocks!)
A canvas bag for you
Bins and baskets
Tape! Lots of tape....
Buttons or other rewards to give out-small items for treasure chest
Fine tip markers like Sharpies
Modeling clay or playdoh
Glitter and other art things (we have paint at our school but I need paintbrushes)
Packing tape (good for securing things to desks)
Painters tape (for marking your things at the end of the year)
Plastic shopping bags
I think this is it for now... I'll have to look around my room later. Most other things, like paper for bulletin boards, chalk, binders, computers, bookcases, globes, CD players, etc are supplied to me. We always run out of construction paper by Christmas, so sometimes I wish I could afford my own huge stock.