In case you missed the notice on the inside front cover of the February Gazette, there is a course to train people to coach Association Croquet at Nottingham on the weekend of 17th-18th May. Please contact Michael Hague (mj.hague#virgin.net) to book or for further information. The cost is £10 for CA Members, £16 for non-members.
There is a similar Association Croquet CTC at Heaton Park on 26th-27th April: details from David Barrett (davidbarrett.db#tiscali.co.uk) and Golf Croquet ones at Taunton Deane on 5th-6th April and Culcheth on 12th-13th April (details on p114 of the Fixtures Book).
There are currently still places available on the Nottingham course; I don't know about the others.
Although these courses are primarily intend to benefit clubs in increasing the recruitment and retention of new members, by enhancing participants' coaching skills, they also benefit the individuals who come on them, as there is nothing like teaching something to improve your own understanding of it.