Light levels at this time of year will work against you Ryan, plus its getting cooler, so unless you have a heated and lit greenhouse I'd leave it a while yet.
But you can plant any number of fruit bushes and trees.
And take some hardwood cuttings from fruit bushes - if you haven't got any you could ask around as see if someone would mind you taking some cuttings
Thank you everyone I guess I was just looking for something to do in the barn this winter
Ryan - if you are in the southern part of England - say from Bristol on down, you may be able to plant some over wintering onion sets providing the ground is neither frozen nor waterlogged - though success is not guaranteed! Sow from sets and not seed. My own experience in Gloucestershire is that anytime up to the end of November is ok, so if you are further south than that you *might* be ok.
I have found that the keeping quality of these is not as good as that of main crop onions so you would have to use them as and when they are ready to be pulled.