Compassionate mothers help make compassionate sons but more importantly, a gentle, loving father who is also consistent and reliable has the most influence on how his son will turn out. Is your sons father this kind of person? Do you know anyone who would fit this mold that could be a role model for your child and be stable enough to be around for a long time? (Maybe an uncle etc.)
I have four boys and just found out boy number five is on his way. Dr Dobson is great but he advocates spanking which I don't agree with.
I have found that its great to read books about each developmental level so you can figure out what behaviors are typical at each age as well as emotional behaviors.
Many parenting books not geared towards boys are equally as good. One I like is called 'The power of positive parenting' by Dr Glenn Latham.
There are a number of good books out there by Richard and Lynda Eyre about teaching your children values and responsibility also.
Both authors have raised several children successfully and so I trust their opinions.
Good luck, having boys is exhausting but so much fun!