Posted: 13/04/2014 at 20:23
Worms are good for the soil, they aerate it and also help to improve it's structure by dragging organic matter (manure/leaf mould etc) from the surface down into the soil where it will add to the nutrients. So they are good for vegetables - in fact they are absolutely necessary to successful gardening.
When growing carrots in containers I found that Chantenay were a reliable variety and very tasty.
As for potatoes - most people will have bought their seed potatoes by now and there may not be much choice in the garden centres - go along and see what they have - I suggest that you get an Early or Second Early variety rather than a Maincrop variety.
Seed potatoes are small potatoes which will have little shoots growing from them. Treat them gently and be careful not to knock the shoots off.
There's a good video here showing how to plant them http://www.bbc.co.uk/gardening/basics/techniques/growfruitandveg_potatoes1.shtml
Good luck and come back with more questions if I've not explained it clearly