Thanks for the information. Are there some locations that are better than others when it comes to garage sales? For instance, would it be worth my while to visit garage sales that are in more "upscale" neighborhoods then the more local neighborhoods? I'm trying to map out a strategy that will make the most efficient use of my team instead of coming at this in a random nature. I will also have to check out some used book stores in the area.
For what I was doing, modern first editions mostly, I found that only around 1/10 would sell on ebay if I was lucky. Actually then I switched to Amazon which is better. Anyway, my point is to make any money, I had to pay very little, less than $1 per volume if possible. So basically, I stop at the sale, ask how much for hardcovers, and leave if it's more than $1. Occasionally you find people who are really wanting to get rid of their stuff and charge $.25. That's rare but great. If it's over $1 I won't buy it unless it's signed.
Condition is everything.
You do find neat stuff out in the country, like at barn sales, sometimes. But remember, it's all about the condition. What you're looking for is perfect, brand-new, never been cracked. That's the holy grail. And it MUST have the jacket.
Unless it's signed Shakespeare, it MUST have the jacket.
Also I had to learn to avoid best-sellers, which is mostly what you find. No Stephen King, for example, unless it's his first book.
It's fun because of the thrill of the hunt.
And every once in a while you find a signed one. I have a signed Charlton Heston autobiography, if anyone's interested.
I have a first edition first print of Memoirs of a Geisha which I got the old fashioned way ( bought it in Waterstones 
