You have a few options here:
1. Microsoft Publisher is a great way to get a professional looking web page up in a short time, with a minimal learning curve. I prefer Publisher 07.
2. Adobe InDesign is a more "designer" focused program. Creativity can be stretched with this one.
3. TopStyle produces a user friendly CSS and HTML editor. Basically, create the whole, simple package in one simple program. Never used it, but have heard good things.
If I were you (or your brother), I would invest at least in Microsoft Office Enterprise, seeing how his business could grow exponentially very shortly. I just got off the phone from my old boss who owns a local, high end construction company, and we had a conversation about how the internet can make or break job efficiency, productivity, and sustainment. It's a whole new world out there. MSOE offers a whole business-centric package of software aimed at productivity, efficiency and sustainment.
Keep in mind, no matter what path you may choose, some education is needed. I am not a school taught computer geek. Everything you need to operate successfully with the aforementioned software is available via the internet. If the price point for the above software doesn't fit the pocketbook at the moment, look into the old school: a text editor, and some tutorials on CSS and HTML. All of which are available online.
That's my word on the subject. Please feel free to PM me if you have any other questions. I do know a bit about CSS...but you know my opinion of web page building now.
Shawn