D.,
By all means educate yourself on Foster Care. One of the BIGGEST behavioral problem is Reactive Attachment Disorder (RAD).
This can be helped and healed. Knowing the number of previous placements for a FChild has had is going to help you build trust.
MANY of the Foster Care kids have attachment issues.
Check these websites, www.radzebra.org. www.attach.org and www.radkids.org (or com) can't remmy this one.
ALL of these sites can give you added insight to the fears a child has when separated from birth parents and they come into care.
You can email me off group if you want to chat some more.
____@____.com
Hope this helps, Above all, I would say foster if this is something G*d is calling you to do.
B.