In article , M Babcock
writes

My other question is with regards to bed preparation. The beds are
raised (although the boards have been taken down and need re-affixing)
and full of weeds, plus one of them is full of Jerusalem artichokes
which I don't want to keep (even though I hear they're expensive, and
wonderful, and stuff). My current plan goes something like this, based
on different things I've read and my (admittedly sketchy) understanding
of British growing conditions.

1. Remove weeds (and Jerusalem artichokes)

Removing jerusalem artichokes will be a challenge! Grow tough things in
that bed that won't mind disturbance as you pull out all the jerusalem
artichokes you missed first time around.

2. Remove raised soil onto tarpaulin
3. Install newspaper 4-5 inches below top soil level, leaving spaces for
root crop rows (apparently this will help stop any perennial weeds
coming back)
4. Replace soil
5. Fertilise and cover with black plastic
6. Leave for 2 weeks, remove any stubborn weeds, then sow seeds

Does this sound reasonable, or even sensible? Is it overkill?

It's not overkill - you'll still be weeding all through the year.
While you're doing the initial sorting of the soil, try to remove any
pieces of thick root that you see - possibilities include couch grass,
which spreads by underground stolons, dandelion, with thick tap roots
going straight down and which will regenerate form the roots, ground
elder, whose roots have a nice fresh potato-ish smell, and bindweed with
long cream bootlace roots.

Don't expect too much this first year. Look and think about whatever
happens, and you'll learn lots for next year.
--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/edward/index.htm