Hi Darren
The best place to start is
http://www.irata.org/The rules and regs regarding roped access are very very strict for obvious reasons.
By the end of the year I'm planning to be able to do roped access not only for window cleaning but for surveying ( by taking pictures etc) and so on and I've looked into it in some detail.
Irata are about the only people who can give you the relevant certificates.
With regards being taugh by someone who'd been on the firm for a number of years, sadly, those days are gone. The HSE etc put a stop to all that and maybe for good reasons
Cheers
Ross