When making your signs, write big enough that people can see the address and date/time. I really hate not being able to see the writing on them.
As far as ordering signs, I wouldn't. Especially since it is a community sale. I totally get not having the sign making skill. I honestly can't even draw a straight line with a ruler. I have shaky hands. When I make signs, I simply write yard sale, the address, and the date/time. If the sign is still in good condition, I will save them, then for the next sale cover the previous date/time with another piece of posterboard and write the new info on it. I also do some arrow ones to put closer to the house.
As far as bags go. I have in the past asked a local store if I could buy a pack of unused bags and they actually gave me a bunch. I have also reused grocery bags. People just appreciate having a bag to carry their stuff. I don't know how many sales I have been to and they didn't have bags. I am always grateful for a bag.
Mom to a wonderful little boy.
We are in Central Indiana.
We do a garage sale every year, and every year we get a ton of compliments on our signage. I think that means we are doing something right!
Many years ago, we invested in these signs:
Hillman Group - 18x24 Corrugated Plastic Garage Sale Signs
Home Depot
Lowes
They run about $7 a piece w/stand, but are completely worth it. They are plastic and very durable. We have used our current set for about 5 years. Our set before this one were all stolen. We had been using the previous set for about 5 years also.
We printed our address in a big, bold, easy to read font on two pages of cardstock to fit within the address block. We trimmed around the address using a paper cutter. Then, using packing tape (it's waterproof), we taped them within the box. Be sure to completely cover all the paper with the packing tape. They will be waterproof and not need to be redone in the future.
Then, we printed big arrows on cardstock and cut them out. We used our personal laminator to seal the pages and make them waterproof.
Then, we printed Sat 8am to 2pm on cardstock and trimmed around them. Once again, we used the personal laminator to seal them. Then, we taped them sticking off top of the signs on both sides.
Lastly, when we put the signs out, we take packing tape with us and tape the arrows on the signs. We keep the arrows so they are easily removable. This way, it doesn't matter where we put each sign.
We have moved three times, and each time we just untape and rip off the address. Then we update it.
I think our signs are effective because they are big, simple, easy to read and to the point.
Most Garage Sale signs are too small, too hard to read, too cluttered, not waterproof, etc.
The better signage you have, the more customers your sale will have.