I've been raising quail for a little over 9 months. Mine are Coturnix, which are also known as Japanese. I have the Jumbo Wild, or Pharoah, type. They take a little over 2 weeks to hatch, need to be in a brooder for about 3 weeks and then can go into their grow out or breeder cage at that point. They need a higher protein feed than chicken. Start them with a game bird started with 28% protein. Advice varies on when you can reduce protein, but I try not to get lower than 22%.
As others have said, they can be quite savage. I've had several scalped by others because I didn't spot the aggressive behavior soon enough. Yesterday was my first cull/harvest of excess males. I'd probably let some of them grow too long, but wasn't ready to start that process till now. It went surprisingly well and I don't think any of the birds suffered much. I've currently got 2 breeding colonies of 1 male and 5 hens each. I also have seven 3 week old birds, 3 male/4 female, that will be going into grow out cages this weekend. I've got an additional 36 eggs that will start hatching next week.
I have enough cage space to handle what I've got and the next hatch. What I would have done different if I could have would be to have more cages, or the materials to build them, along with more space. Currently, they're in my garage and doing fine. Within a few months, I'll be moving to a 2.5 acre property and will have a lot more room for the birds, so more cages to come.
I enjoy the birds and plan to keep them. I'm getting plenty of eggs and hope to be able to start selling some to help recoup the cost of feed.
If you don't want to raise them for meat, I'll echo
@Nabiki and suggest just getting hens from the farmer instead of hatching eggs. It may cost a bit more, but getting rid of excess males can be difficult if you don't want to harvest for meat.