Looking for help and guidance in installing ArcGIS for Server. any suggestions?
The following link can help you and gives a step-by-step for the installation and setup.
ArcGIS for Server system requirements—Installation Guides (10.3 and 10.3.1) | ArcGIS for Server
Do you have any specific questions? Chad gave the installation guide; be sure to also read over Best practices for configuring a secure environment—Documentation (10.3 and 10.3.1) | ArcGIS for Ser... - it's important you make your installation as secure as you needs will allow.