The study is done to find out what the living conditions are, whether or not they appear suitable and appropriate for a child to live in, and whether or not there are hazards or deficits in the living arrangements that might be detrimental to the child. Home studies may be performed by various parties such as Child Protective Services case workers, CASA's (Court Appointed Special Advocates) or GAL's (Guardian ad Litems).
A home inspection may also be paid for by your spouse, using a a private inspector as an "expert" to go out and check your place out (and obviously, to make it sound as bad as possible). If this is the case, you may need to get your OWN inspector to dispute that report.
Regardless of the cause, fix your home up as much as possible. Take plenty of good, clear pictures of the house and the room(s) for the children, the yard where they play, etc. You may need to show these to the Judge as proof of the general state of your home environment. Remember that access to community services and recreational areas - like parks, etc., are important as well. Be able to tell the Court about all the opportunities there are for the kids in your neighborhood and surrounding areas.
During the home study, different home study evaluators look for different things, but there are some things they all look for:
Is the home safe? Are there hazards present that go above and beyond the typical things that might be found in any home? For example, such things like unsanitary conditions, exposed electrical wires, broken steps or handrails, sharp-object hazards, broken windows, and so on. These may be referred to as "gross hazards".
Hot tubs, pools, spas, and saunas are also hazardous to children. They should be secured in a way that prevents children from opening, entering, or operating them. If you have both a pool and young children, restricted access and a pool monitor or alarm is a must.
Is the home reasonably clean? A home doesn't have to be surgically sterile, but many home evaluators can tell stories of finding cat or dog feces littering the living areas, kitchens filled with rotting food and garbage, and bathrooms that obviously hadn't been cleaned in months (or years). Your house doesn't have to appear ready for a Better Home and Gardens photo shoot, but piles of clothes, toys, pets and junk strewn around the living areas will not impress the home study worker.
Have at least one suitable fire extinguisher located on each floor of the home, and have a working smoke detector in every room. Fire extinguishers should be securely fastened to the wall with proper mounting hardware (virtually all come with a mounting bracket). We also recommend purchasing and installing one or more carbon monoxide detectors. (Frankly, this is equipment you should have whether you have a home study or not.)
Make sure all prescription medicines and cough/cold remedies are stored safely out of reach of the children. The same goes for household cleaners, detergents, paints, solvents, etc. These must all be stored in such a way that it is not possible for a child to get a hold of them.
If you're a fan of "racy" magazines like Playboy, Penthouse, etc., either get rid of them or store them out of sight. It's a free country and there is no law against having or reading these kinds of magazines, but the impression they'll make on a home study worker will probably be less than optimal. The same goes for adult videos- store them out of sight in a place where the children cannot access them.
Is appropriate food for a child available? Home study workers like to see a well-stocked refrigerator, with plenty of fresh fruit, milk, bread, cereal, and other staples. If they open your refrigerator and see a nothing but a six-pack of Bud, a stale taco and jar of Velveeta Cheese Spread, you're in serious trouble.
How does the child's bedroom appear? Is there a suitable bed with clean blankets and sheets on it? Are there age-appropriate toys in the room? Are the electrical plugs covered or capped off? Are there locks on the doorknobs? If so, replace them with the non-locking kind. (For a variety of reasons, some social workers don't like to see a child's bedroom with a lockable door; the same applies if they have their own bathroom.) The room should be reasonably clean and neat, and it should have all the typical furniture you would expect to find; a bed, dresser, a chair and table, lamps, etc. A bare room with just a cot and chair is going to look more like solitary confinement than a proper child's bedroom.
A special concern about firearms: Along with the rights we have to own firearms comes a responsibility to make sure that they are inaccessible to children. Home study workers are often very liberal and may be especially sensitive to the whole concept of firearms ownership. It's best to keep them completely out of sight under lock and key. If the subject comes up, downplay it. If necessary, show them that the firearms you own are stored responsibly where the children cannot get to them.
What are the other family members or residents like? A home study worker likes to see a balanced family setting if possible, but as long as the other people in the home don't pose a threat (real or imagined) to the child it's not usually a point of contention. A roommate who is on parole, or who has a drug or alcohol problem will generally not be considered a suitable person to have around children.
It's also a good idea to make sure you have your tax returns and W-2's for at least the prior year, marriage and divorce decrees, check stubs, past work histories, references, and your family history (when mom married dad, etc. etc.). You'll need the year and dates for everything...when siblings were born, city and state, etc). Definitely make copies of all of this for him/her to take with them, DO NOT allow them to take the originals.