Check out http://www.gedenkstaette-grafeneck.de/329.htm and click on the tab labeled "visitor." It has to an address to contact for information on the victims. If the site comes up in German, it may have a spot to click on "English." If not, go to Google Translate, set it for German to English. Paste the web URL in the German spot. It will come up in the English spot and look exactly the same, like it hasn't done any translation at all. BUT, if you click on the URL on the English side, it will open the website in English.
LDS has filmed the records of the Steinsfurt protestant church, so you can get them on microfilm in this country via your local Family History Center, without having to write to the church. Here's the catalog listing of the film #s for the various years.
Re German script. When I'm doing research, I carry a chart similar to page 2 at http://www.ggrs.com/events/handouts/handout_script.pdf. This is obviously a lot neater than acutal handwriting, but it's a starting point. Then, before I look for any specific names, I make myself another chart, with the letters of the alphabet as we know them in one column. Then, I look at the record--doesn't matter for whom, just pick any words you can recognize out of any record, and copy the letters as they're written on the document into the second column. To look for a specific name, use this newly made chart and write how you think the name would look in the handwriting. If the handwriting changes within the records, you may have to do this more than once. I have found translating the old German is a long and tedious process, but gets easier the more you do it.
I apologize for not responding to your earlier email. My son got married this past Saturday and the last couple of weeks went by in kind of a blur.
I discovered I wrote too much to include in one genealogywise message, so am splitting it up into however many it takes. I found the website for the church, with address, that I've sent in its own message, but I think I may have found you something better. You gave me Mina's name in an email you sent me a couple of weeks ago so I was able to use it. Go to familysearch.org and search for Mina or Wilhelmina Grob in Sinsheim or Steinfurt. Several records will come up, including a marriage of Mina to Jakob Braumer on 20 March 1868 in Steinsfurt. The actual record isn't there, but the LDS film # is included, and you can order that through a Family History Center. You don't need to be Mormon to use the center. (I'm not part of their religion, but have used their resources extensively and have everyone at my local center to be friendly and helpful.
I did not find anything on this site for a Mina Grob in Switzerland, but that does not mean she wasn't there. I have only tried a tad of research in Switzerland (my husband's great-grandmother came from there), and I am finding it very difficult. Switzerland has strict laws protecting information (that's why people hide money in Swiss banks). The best information I've found about doing genealogical research in Switzerland is http://www.eye.ch/swissgen/gener-e.htm.
I couldn't find anything for a Steinsfurt Rathaus, but I found a couple of articles that referred to Steinsfurt as a suburb of Sinsheim and one said it shared a mayor with Sinsheim and they have the same mail code. So, I'd try one of two things. Either try addressing a letter to Rathaus, 74889 Steinfurt, Germany, or write directly to the Sinsheim Rathaus, since it might be the same place. I found it's address: Stadt Sinsheim | Wilhelmstr. 14-18 | 74889 Sinsheim | Tel: 07261-404-0 | email@example.com.
By the way, there are post 1870 birth and marriage records in the LDS catalog at familysearch.org, so you may want to order those too, if you're looking for children of your great-grandparents.
That film # was for the protestant church. Death records for the Catholic Church only go as far as 1900 and are on film # 1049304.
For civil records, you could try writing to the city hall (Rathaus) of Steinsfurt. I don't know if the records would be there or would have been moved to the Baden-Wuerttemberg state archives but the Rathaus could probably tell you that.
I checked the catalog on familysearch.org and didn't find any familienbuch for either the evangelische or catholische churches in Steinsfurt. I don't know of any other place online that would have this information. Perhaps you could try writing to the church and asking if they have the information at the church.
But, according to familysearch.org, Steinsfurt death records for 1870-1908 and 1908-1963 are available on film #1189151. It's possible that a death record for Susanna Kistler Grob, if the family didn't move and she died in Steinsfurt, might give her birthplace. Do you have parents' names for her? If so, you might try looking for them on familysearch.org.