Very straightforward process. Arranged a convenient time for you to go to their local office to fill in forms and provide your documentations. You just let them know what you want and the kind of school you'd like to teach in.
Interview questions [1]
Question 1
Are you looking for long term, permanent or short term roles?
I applied in-person. The process took 1 day. I interviewed at Randstad (Cambridge, England) in Jan 2012
Interview
Send in or, even better take in, your cv and certificates, ID, and any other possibly relevant documents. They will ask you about your experience and your strengths and weaknesses - try and have examples in mind.
Interview questions [1]
Question 1
No especially difficult or unexpected questions as I recall.