Browsing through a couple of HSE guidance publications would be useful - HSG85 & HSR25. They are available to download as pdfs FOC from the HSE website. We use the MOD rules as a reference, so if you could get a look at the JSP 375, v3 ch3, this would also give you a head start, again available to download but from the .gov website. Please note I recommend 'browsing' these documents because they can be hard going without the context that is explained during the course.
A more valuable resource would be current APs. If possible, shadowing an AP would help with what your expectations should be and give you some prior understanding.
I hope this helps... G.
