My step children are grown now and have children of their own now and this is advice that I wish I would have had 20 years ago.
1. Do not be afraid to allow your children any relationship with their natural parent. This is true even if the natural parent can have only limited contact with the child.
Over time the child will learn that you became their step dad because you care about them as an individual and you took on the responsibility of raising the child.
2. Many children feel it is their fault that they do not have their natural parents. It is not and it is your job to help them heal from the trauma that they have experienced in their life. Sometimes that means hiring a professional counselor to assist you.
3. Never get involved with comparing the life they had with the natural parent and what you offer the child.
4. Do not be offended if the child can not or will not call you dad. The older the child is when you become their parent, the more difficult it is for the child to accept you as their dad.
5. Do your very best to accept the child as some one with valid dreams, hopes and aspirations. You will have to deal with rejection and anger as the child works through the emotions that brought them to the point where they are.
6. Do what you have to do to enable the child to trust you absolutely. This is vital. If the child does not feel they can talk to you about anything and everything, you have failed that child as a stepfather.
7. If their is visitation with the natural parent from a previous marriage, always attempt to be on good terms. If you have a beef, take it far away from the child and settle your affairs privately.
8. Discourage any negative talk from your spouse about his or her former spouse. It does the children no good and leads to further heartache and difficulty for the child.
9. If there are children from your marriage or previous marriage, make sure to allow the children time to become friends before they come to live with the new family.
10. If there are visitations and the family situation is some what fluid, always make the visiting child feel wanted and loved in your home.
11. Always make sure the stepchild has some place and some things that are uniquely his or hers. This fosters a sense of belonging and being wanted.
12. When times are tough, and there will be many of these times - remember this too shall pass.
And finally God bless you for taking on the task of helping to raise a child that is not yours biologically!