Raspberries

You can prune in late fall or early spring. The canes that had fruit this year wont fruit again next year, the canes will look greyish and the bark may be peeling, you can prune those out. I always found it easier to identify those in the spring when the newer canes start to leaf out.
You should thin them out so that the best canes are left, maybe 4 to 6 canes per foot of your row. Heard that if you prune whats left down to about 10" new shoots will grow off the canes in the spring and bear fruit, this gets you one harvest in the summer. I have never used this method, just pruned out the old canes and left the best for next summer.