Wiki is usually a good starter
Formation Reconnaissance regiment
As to who did what and when and where - try looking at the regiment histories at
www.army.mod.uk - here is
2RTR History. Regiments (cavalry or infantry) re-role from time to time.
Note that UK does not have "heavy" recce regiments, like US Armored cavalry, or the FRG ones with Leopard tanks etc. UK recce units are focussed on "makee looksee" and not "makee fightee" - so have only enough firepower to keep themselves out of trouble.
The UK recce regiments would be used as part of the screening forces forward of the BAOR deployment areas - delaying and reporting, using the swingfires to attrite any enemy armour that got too "frisky", and calling in air and arty etc to do the main work. The radios of the regt, and its mobility are the primary weapons.
Cheers
Andy