There was a cheap exercise bike on offer next to a cheap cross trainer in Tesco at lunchtime.

Probably be some change from £100 to put to your medical bills for when they collapse.

Where to start

As a minimum, assuming you've got some basic kit to wear (including a waterproof), I'd say you need something like:

Helmet (up to you I guess but I've seen enough people crack helmets in crashes to convince me that they're worth wearing) £50
Pump (preferably a track pump with a pressure gauge so you don't get lots of punctures from having tyres too soft) £20, plus £15 for a mini-pump or Co2 for the road
Multi tool £15
Lights - basic set £30ish?
puncture kit and spare tube - £15
Chain tool and 'powerlink' - £15.
Gloves £15
Cycling shorts £20
Lock if you're going to be leaving it anywhere unattended.

prices are rough guesses for decent budget kit. Good enough to start out with anyway.

I'd also add a lot more stuff, but you could probably cope with that. Might be worth asking someone who only cycles casually what stuff they definitely need

re: bike, check with the local bike shops (proper bike shops, not big chains). Should be able to get something decent for £300 to £350.

Look up Specialised Sirrus, Scott Sub 40 or Cervelo R5ca for a rough idea.

Mind you, if you live near some good trails you may ride a MTB more - hybrid is the jack of all trades but you need to have an idea of where you'd be riding.

Of course you could always just buy some trainers and start running

I smiled when I saw that, if you mean the Toys R US roundabout Tescos.

You stalking me?

They tried to rip me off over a Food Processor - I have been inspired to be more healthy etc..........

Only stalking you if you were in there when the tall blonde woman with huge heels and a grey cape was there.

Grey It's "abysinnian slate" actually.

I wasn't asking if you were her, she made a change from the usual bland fuglies that go there.

(I doubt that your legs are that good, anyway )

Which ones??

dunlop green flash

Doesn't really matter which ones you have. Personally I always have Brooks GTS, but that's because I have a tendancy to pronate. And the Brooks GTS have extra support to combat pronating.

Just make sure you replace them every 500 miles or so (of running obviously)

I would suggest looking for a free cross trainer on craigslist or freecycle.

This will allow you time tosee if it's for you, what features you like, don't like and then buy one to your own tastes (or join a gym, go swimming, bike, running in green flash dunlops etc)