Documenting System Configuration and Setup

I am working on system documention for our procedures in setting up end user laptops and desktops. I was wondering if any of you had a good template you use or a link to a site with some template options.

No, it shouldn't be hard, but there's no need to recreate the wheel if a good solution is already available.

Also, what software do you recommend for templates like this? Historically I've used Excel, but I'm open to improving my processes as well...

Thanks in advance for any assistance.