I have to agree with Erin - Most Canadians (as well as Aussies, Kiwis and South Africans on YMV's) seem to move to London and seem to believe that it's impossible to find work and exist outside of London.
London is really not a very nice city at all in my opinion - like all capital cities it suffers from sky-high prices compared to the rest of the country.
Aside from the prices, it doesn't have a lot going for it - it takes over an hour to get from one side of the city to another, it's very densely populated and the people are obnoxious and rude. Rush hour is an absolute nightmare, especially in places like Waterloo, Kings Cross or anywhere on the tube for that matter. Remember there isn't the room to spread out and build like in Canada so it feels very claustrophobic.
Cities such as Bristol (south-west) and Leeds (north) have been redeveloped over the past ten years and have built large financial service sectors, so they offer just as many opportunities for administrative office work if that's what you're after. They are also just much cleaner, spread out and greener cities to live in and the people MUCH friendlier as a result.
You also have Edinburgh and Manchester as options.
It just irritates me when all people talk about is London. London is NOTHING like the rest of the UK, and this is why English people can often be heard half-joking that it is a separate country in itself. I just don't understand why anyone would want to live in London.
Re; the cost of England. OUTSIDE OF LONDON the prices for virtually EVERYTHING is considerably cheaper than Canada. Food is much cheaper - you can easily live well on £20 a week for food/groceries as there is so much supermarket competition here prices are rock-bottom. Alcohol is probably 50%+ cheaper. You can get cans of beer in Tesco for about 80p each if you find the deals, and even if you can't you can buy exceptionally high quality microbrewed ales or even German/Belgian imported beer for about £1.70 a large bottle (over 1 pint). Decent wine for £4 a bottle. Cheap vodka, whisky starts around 8£ for 750ml.
Transport is cheaper - Megabus.com offers dirt cheap bus and
train tickets for inter-city travel. You can pick up tickets for £2 or £3 if you book ahead for 4 or 5 hour journeys. Much cheaper than Greyhound and the terrible train services in Canada.
Air travel: Ryanair and Easyjet you can pick up tickets with these
airlines for sometimes £10 one way from
UK to cities on the mainland. Bristol to
Morocco is currently £20 each way. Infinitely better than
Westjet or anything North America has to offer.
NHS: Yes, it has some problems (that are usually over-played in the media), but it's a billion times better than the 'health care' system in the US and it's universal and free (just a small contribution each week from your salary, something like £5 in the low tax bracket), so generally is better than Canada. Prescription costs are about 7 quid in England for any medicine you need and completely free in Wales and Scotland. Painkillers like tylenol and ibuprofen can be found in shops for 20p a packet. So about 500-1000% cheaper than Canada.
Convenience; England has shops selling ready made sandwiches, baguettes even sushi from about £1 on virtually every street corner. That just doesn't exist in Canada. You have to hunt around malls to fork out 6$ for an equivalent snack. So again it's probably about 500% cheaper and more readily available.
Post Offices; UK post-offices don't just send mail for you, they also change money (at the best rates, commission free), change travellers cheques (again, commission-free) offer travel insurance etc etc.
As for salaries, bear in mind the pound is weak at the moment compared to the Canadian dollar, that is doing well from oil exports and hasn't been affected nearly as much as the UK in the recession as a result. This makes it appear that salaries are lower because the exchange rate is abnormally low at the moment. For example, 2 years ago you got $2.50 for £1.00, now its around $1.50 to the pound. So it may seem that salaries are low here - they are not, because it's all relative to how much the cost of living is in the UK. The prices reflect the salaries, and the UK is still considerably cheaper than Canada in virtually every area other than leasing or buying property. Even then, the cheap food, medicine/health care, alcohol and transport makes up for it.
In conclusion I wouldn't base your research solely on London - talk to people who live outside of London in wonderful cities like Bristol and Leeds. Yes, the economy is bad right now, but depending on your qualifications/experience you still have as good as chance as anywhere in getting a job. If you aren't fussy you will definitely find work. It really depends on what you want to do and what you enjoy.