SAP S/4 HANA 1809 Tutorials:
https://education.hana.ondemand.com/education/wa/s4/index.html?library=library.txt&show=group!GR_F64A03A70C1AEB82#
SAP Best Practices for SAP S/4HANA (on premise) (USA)
https://support.sap.com/content/dam/SAAP/Sol_Pack/BP_OP_ENTPR/BP_OP_ENTPR_S4HANA1809_05_Content_Library_EN_US.htm
SAP Best Practices for SAP S/4HANA (On Premise) (Deutschland)
https://support.sap.com/content/dam/SAAP/Sol_Pack/BP_OP_ENTPR/BP_OP_ENTPR_S4HANA1809_05_Content_Library_DE_DE.htm
SAP Best Practices for SAP S/4HANA (on premise)
https://rapid.sap.com/bp/#/browse/packageversions/BP_OP_ENTPR