You didn’t mention your son’s age, Bethany, and that is important. Since you say he has “just recently been learning to read,” I am going to guess that he is 6 or 7. If so, I would not help him if he just reads a word wrong, unless the error changes the meaning of the sentence.
However, I would help him if he gets stuck and can’t go on. If he becomes bogged down on a difficult word he is not likely to know, I would simply supply the word. If he gets stuck on a small word or a word he has previously read with no difficulty, help him. If the error occurred on a word he had successfully read earlier, point to the earlier word and ask, “What is this word?” If he remembers, or figures it out from the context, just smile and say, “That’s the same word you had over here, isn’t it?” and let him go on reading.
If he is getting any phonics training in school, you can help him use his knowledge to sound out the word that gave him trouble. If it’s a two-syllable word, you might cover up the second syllable and see if he can sound out the first. (It is amazing how much of our reading is based on a quick glance at the first syllable.)
The most important thing is, as you comment, not to shake his confidence. Praise him for what he read and offer an encouraging comment at the end of the session: “You are really coming along nicely in your reading. Before long you’ll be able to read just about anything.” And don’t let the sessions become stressful. If you sound upset at his performance or offer too much criticism, he will stop wanting to read. Keep it light.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.