I saw this advice on (of all places) the Dr. Phil website. Now, I'm not a huge fan of his or anything, but I do think this is sound advice for some of the issues I see single mothers dealing with:
"If you're a single mother, you may have to deal with a father who isn't very involved in your child's life. How you explain the situation to your child is important. Dr. Phil shares his advice:
1. Realize that no matter what you do, you can't force your child's father to be involved.
2. Although having a father figure is important, it's not everything. As a good mother, you don't need a father to raise your child in a quality fashion.
3. Forcing a reluctant father to talk on the phone will only confuse your child.
4. If you try to force a relationship with a father who doesn't want one, your child is bound to feel disappointed and rejected.
5. Don't talk negatively about your child's father, but don't glorify him, either.
6. Leave the door open for responsible contact between the father and your child."