Thank you for your post.
Let's first start with the file(s) you want to display. From the File menu, select "Sharing -> Instant Web Publishing..." Turn on Instant Web Publishing, and write down the IP Address (unless you already know it). In the bottom left, select the file, and on the right side, set access to All Users (for now).
Next, go to another machine, launch a browser and enter:
You will now get the Instant Web Publishing page where you can select the file and see how it looks. Feel free to look around. Don't worry about being able to edit everything right now. When finished, click Log Out.
Return to the machine where FileMaker Pro is running, pull down the File menu and select "Manage -> Accounts & Privileges..." Check the "Guest" option, which only gives you Read Only access. After clicking OK, return to the other machine, launch the browser and access the file. This time, enter a Guest account. Now, you can only view the data and not change it.
This should get you pointed in the right direction.
Web Viewer Example.fp7 is a sample file, and you have full access to it. Just open it in FileMaker Pro, look at the field definitions, layouts, etc. I'm not familiar with the Matrix Report, but you should be able to find locate it as one of the layouts.
Please let me know if you need clarification for any of the above steps.