I tried to plant asparagus before, but it didn't work out well - there was one single fern from the three I planted, and then nothing the following year. I'm not sure whether the soil was to blame (a fair chance), or my possibly inept planting (also a fair chance). The fact that I wasn't 100% sure what an asparagus fern looked like was of no help in this.
The two apples we have, and the pear, are at the back of the garden, and except in the height of summer, they're in the shade of the south wall at noon. They get some sun in mid-morning, and a little in the evening. As they grow higher, of course, this to being less of a problem, and to be honest, they don't seem to suffer much from it even now. They're quite close together, but as long as they're kept pruned back to reasonable sizes, they should be fine. I did see apple trees at the Bloom festival last weekend which were plainly twenty years old or more, but which were not much taller than ours now - they'd been kept trimmed back very nicely, giving an effect almost like bonsai.
Some of the fruit bushes - particularly the gooseberry - are coming into their own. I'm debating not pruning the smallest currant this year - it looks like it could use some more physical mass - but I'm honestly not sure whether that's better or worse for it. I'll have to do some reading.
And then there's the aforementioned rhubarb and asparagus. I need to work out what they need, when the ideal time of year is to plant them, and then find suitable spaces in the garden that I can be relatively sure won't be disturbed for a number of years. My instinctive urge is to have them near the edges, but that's not necessarily useful, or even convenient - why shouldn't there be a great big bed of rhubarb in the middle of the garden? Indeed, given we've a slightly inconveniently located plum tree, I could do worse than plant rhubarb around it.