Middle stages of 20 and 30's on Pokerstars

[tomscuba]

I'm posting this question that my dad posed to me, and I don't have advice I can give with confidence.
It relates to the middle stages when there are 5ish players and a blind round is getting to be about 1/6 of your stack.

Any simple rules about hand values, table image, positional aggression----anything---that would be helpful to 2 relative newbies?

Thanks for the time,
Tom