I would also be honest and just answer questions without being to graphic. Only reason I say this is that very little kids can get real confused if given info which is beyond them. For example my DS aged 4 is very interested in hearing about my dad who died (28 years ago mind you) to the point of obsession sometimes, and in the course of MANY discussions he asked where bodies go so we had a talk about coffins. Well DS aged 3 overheard and the other day said "Poppy Ivan died along time ago so Grandma put him in a die-box as a present".
I know this sounds like I am making a joke but I'm not - but just mean to say little kids take in a lot and it doesn't necessarily freak them out as much as adults think it does.
Hey babe. I just thought I'd mention something else that was told to me by a friend of mine - when you talk about the star in the sky, you can say we (insert your family name) believe that... This means that if he gets into a discussion with a friend or teacher who tells him something different you can explain that that is what your family believes. (Like if someone talks to him about heaven and you're not comfortable with that belief, you can reiterate that you believe... etc).
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