Two plants, two opposite prunings
Summer-fruiting raspberries crop once, on last year's canes. After harvest you cut to the ground only the canes that fruited, and keep this year's growth for next season.
Autumn-fruiting raspberries crop on the current year's canes. The simplest management is to cut everything to the ground in late winter: you give up the small summer crop and get a good autumn one, with nothing to decide.
Pruning a summer type as if it were an autumn type removes the entire crop. It is the commonest mistake, and it only shows a year later.
What the fruit is not
A raspberry is not a berry. It is a cluster of small drupes, each with its own seed — the same structure as a blackberry. It separates from its receptacle, which stays on the plant: that is what distinguishes it from a blackberry, which takes the core with it.
A picked raspberry does not ripen further. It gains neither sugar nor aroma after picking — which explains the gulf between a garden raspberry and a transported one.
What it needs
Cool, rich, slightly acid soil, never waterlogged. A thick mulch, because the roots are shallow and suffer quickly in drought. Bright exposure but not scorching — in hot regions it prefers part shade.
It suckers strongly: without a physical barrier a raspberry bed becomes a thicket in three years.
our piece on flower symbolism places the raspberry among the plants that mark the seasons.