In reply to StephenAS:
Burbage South valley boulders is a great place to start (or continue) outdoor bouldering. Perfect landings, lots of slabby problems to learn grit footwork on, nothing too high, gorgeous place, super-easy to get to (very close to parking if you have a car, very close to a bus stop if you don't). You can have a nice day there with a single mat between a group:
Burbage South Valley Boulders
Also, I'll be the pedant before someone else is: "free climbing" just means that you're not aid climbing (using gear to pull up on or stand on, not much practised in the UK -- it's most often used for big wall climbing in the US).
You might be thinking of "free soloing", but that applies to climbs above bouldering height -- generally, stuff where you'd potentially be seriously hurt or killed if you came off.
Also, what JonStewart said: buy or rent a mat, and go expecting it to be utterly different from indoor bouldering and to kick your arse at first. That happens to everyone, so don't be disheartened. It's a learning experience, especially with grit (which is the most different from indoor climbing, at least in my experience).
Have a great time!