What exactly do they/you do or have to have or look for in a Home Study.
My home study was two hour interview with a licensing specialist with a private agency in Michigan. She checked for compliance with state regulations (hot water temp, correct spacing between slats on the crib, over all condition of the home etc.) and they talked with my husband and I. She wanted to know strength and weakness, family dynamics, communication style, awareness of issues with foster children and awareness of regulations. For us it was an informative and friendly experience. Best of luck to you.
It might vary depending on what your plans are. The physical requirements should be standard within your state - they may ask about fire exits and extinguishers, number of square feet of floor space per child, locked storage for knives, medicines, alcohol, firearms, chemicals like cleaning products. They may want to see that your house is a normal level of clean, that you keep a normal amount of food on hand; basically general safety issues.
For infant adoption, they may talk about your income, plans for working/childcare, attitudes about discipline, education, religion, other kids in the family, experience with children in general, whatever, to get a sense of who you are as parents. There aren't exactly right or wrong answers (unless perhaps you are working with a faith based agency).Of course you will want to paint yourself in a good light, but basically, it is best to be honest. Some homestudies go into great depth about your own upbringing, your marriage, employment history, mental health history, drug/alcohol use to the point that it can feel intrusive. I have even heard that some agencies will do an internet search, look at your facebook page, whatever they can to learn.
For foster care, it might be all of the above, plus discussion about the legal issues of raising a child who is not "yours", how would you cope if the child is moved, what do you know about childhood trauma, could you interact with the biological parents, things like that. If you have kids already in the home, they may want to interview them, to get an idea of their feelings about new siblings.
I am not sure this is true with the state foster care system, but in my experience, the private agencies are working to screen people in, not screen them out. Although the whole process feels judgmental and awkward, they really want to say "yes". They will work with you to explain or excuse or understand an arrest record, a divorce, a bankruptcy, a bad period in your life. Whatever "blemishes" you may have, it is better to bring it up and talk openly, than to have it come up in a background check or whatever.