Thank you for your post.
Launch FileMaker Pro, and open the file you want to use with Instant Web Publishing. Pull down the File menu and select "Sharing -> Instant Web Publishing...". Turn on Instant Web Publishing, click the file in the lower left corner, and then set the access on the right side to "All users". Your file is now set to be used with Instant Web Publishing. At this point, with FileMaker Pro still open, launch a browser and enter the IP address of the machine as the URL, and the Instant Web Publishing page appears where you can select the file.
Once you log out, copy the file over to FileMaker Server Advanced into the Databases folder, and launch FileMaker Server Advanced. If Instant Web Publishing is turned on, you can then have remote users access the database file using Instant Web Publishing.
If you need clarification for any of the above steps, please let me know.