We have ours (Joan J, but also autumn fruiting) in rows about 2ft apart. Each row has a post sunk at each end with two strands of wire between, one about 2ft of the ground, the secong about 4ft up.
I think we put the canes in 18" - 2ft apart; they should be cut down to the ground around February. In autumn fruiting varieties, the fruit is produced on canes grown that year.
We always put on a good dressing of manure in late winter / early spring. As the new canes grow, tie them in regularly - or it will be like a jungle and hard to get in to pick (that's what happened to us this year).
We were picking rasps unil the end of October