I have a question regarding those items/spells which have as a condition of their use 'before/after' rolling'. Does this mean that they have to be used before (or after) rolling any dice, or an individual roll. In other words, which is correct?

1) I have to use the spell/item before starting to roll any dice for that particular adventure - or, if the condition is 'after rolling' after I've finished rolling all the dice I can, or wish to.

or...

2) I can roll the dice pool, possibly complete an individual task (or not), and then, with dice still remaining in the dice pool, use these types of items and spells then.

Any help much appreciated

After each attempt to solve a task, not before / after deciding which adventure to attempt.

Please note that rules for spells were changed in the later printing of the game: they are to be used after rolling, not before.

Thanks very much for your response. I see what you mean about spells, but there are certainly items which still have 'before rolling' as a condition for their use.

Just to be absolutely clear (or possibly pedantic), if I understand correctly the word 'rolling' in this context means each individual roll of the dice pool, not the entire process of rolling all of the dice for that particular adventure?

Yeah, exactly. Each time you put the dice in your hand to attempt a specific task (not when choosing a specific adventure)