This document is being flagged up in lots of the teaching pages i've liked on Facebook:
literacyforpleasure.wordpress.com/ta-guide-to-listening-to-reading-making-comments/
It's terrible, full of recommendations to encourage children to guess. Really depressed at the number of teachers tagging others to flag it as 'useful'. It really, really isn't.
If you're starting as a reading volunteer in September, I hope you're not given anything like this. Any advice encouraging children to guess words is really poor and awful practice.
If a child is 'stuck', encourage them to look at the sounds and blend - or if they're really stuck, give them the word and come back to it later. Feedback to the teacher on the sound they couldn't recognise is fabulous.
And thank you for volunteering in the first place - your help is invaluable and much appreciated.