These are the best resources I’ve found online for divorce in South Dakota. I haven’t yet identified a DivorceInfo Network Lawyer for South Dakota.
Here’s a pamphlet on Divorce from the State Bar of South Dakota. If you don’t need a lawyer and just want to file a simple divorce, you can order the forms and do it yourself, or you can get DocuPro to do it for you.
Here’s a Child Support Parent Handbook and the page on Child Support from the South Dakota Department of Social Services. And here’s the page where you can figure your own child support in South Dakota.