Connecting SQL Server box to my IIS 8 box

jcarrillo26

[h=1]How to setup sql server express 2012 to my webserver?[/h]
I am fairly new to working with webservers and database servers. I was to do this the most pain less possible way. Okay i am doing a project to make a fake company i am to create a website that does some functionality. Anyhow i have a domain that created for this fake company. I have a dc, a web server, and database server. All of the servers have joined my domain and are all responsive to another. I can create a simple database but unsure how to get my web server that has php to work with my database server so i can create this website and host it on my webserver. How can i go about doing this? I have researched because the database and web server are not on the same box i have to install sqlserver drivers etc. I have tried to find tutorial but cannot find any that really explains the details step by step please help.

All of my boxes are 2012 r2 except my domain controller which is 2012. I know this might not be the best place to post but i need your professional opinions how to do this. Please help.