There is a national shortage of square dance callers in the UK at the moment (and probably also some other European countries) so caller schools are now being run each year.
Each caller school lasts five days and covers choreography, stagecraft, sound engineering and sight-calling. This is followed up by two years of support from a mentor. To be eligible for caller school, you must be thoroughly familiar with the Mainstream syllabus as a minimum requirement and willing to teach beginners to Mainstream level (either in clubs or in adult education colleges) upon qualifying. Training in square dancing ab initio is available from a number of clubs, all listed on www.uksquaredancing.com
(look for those marked with a T for teaching). Most courses start in September but a small number of clubs admit beginners all year round and if you have plenty of experience of Playford dance you will know about a third of the initial syllabus (to Mainstream level) anyway.
If you are interested in a career as a caller (you would easily be able to cross-train to teach Playford or Regency dance as well) please get in touch with me. I can also be reached via my Facebook page Square Dance UK, which all UK residents are welcome to join, as are those who visit the country regularly for square dance events.