Who can give me some info on growing blueberries for commercial sale?

They need a lot of water (grows great in aold swampy areas) but must drain they don’t like their roots constantly wet, high levels organic fertilizer and acidic soil. You would be smart to build a bird proof cage around and over them.
I had a friend that bought a house and a 45 foot by 25 foot enclosed blueberry garden came with it.

How long to they stay fresh after picking? And can you get them to the market in that amount of time?

My experience is from the consumer end, A farmer at my local (trendy hipster) farmers market sells frozen blueberries from big coolers.

She has a display explaining the advantages of freezing. The prices are higher than typical grocery store prices.

She’s been there for at least 5 years, so I assume it’s profitable.

Most of the blueberry producing states and regions in the USA seem to have a blueberry growers’ association. I’d start there – google being your friend and all – regarding growing and marketing tips. After that, I’d say it’s time to be creative in the cooking end. Personally, I never much cared for blueberries except on cold cereal, pancakes, muffins, and eating straight off the bush.

You probably want to study up, there is a lot to it. Different varieties produce at different times in the spring and summer, some need another plant to pollinate, some don’t.
Most growers spread the varieties out so they are producing all summer. I have a couple that produce in mid spring.

Blueberries grow well in my climate (near Lake Ontario) Region hardiness 6a, and cooler 5b. It tried doing it twice and gave up.

Deer were a huge issue. They ate all my plants as soon as they outgrew the protective tubes. So frustrating.
Long legged rats.

I went blueberry picking once. I was thinking of the fun times I’ve had strawberry picking, which fills containers quickly. Blueberry picking is way more work. We ended up with about ¼ of a pot full and then we went to the gate of the farm and ended up buying from the guy, pre-picked.

I can buy a large container at Costco for as little as 3.99 (18 oz) so that’s where mine come from.

@MooCows is your farm organic? That would make a difference in the customers you have. Also, try talking to local stores in your area to see what prices they would offer you.