The Illustrated History of the Roman Empire website is just that — a neat historical site with loads of pictures and interactive map. There is lots of fodder here for historical wargamers.
Eye candy time. Here are some pictures of really well-done Early Imperial Romans. I like to have pictures like these to use as a painting guide.
The Warhammer Ancients rules book is full of point values, but it’s sometimes difficult to tell exactly how many of each troop type you should have. If you’re into Romans, here’s an example army list for you.
This free paper model of a Roman villa seems to be somewhere between 15mm and 20mm size. You could scale it on your printer, though to make it work in other sizes.
Legion and Empire is a set of free wargames rules for the Roman era from the Punic Wars (264 BC) to the fall of the Western Empire (476 AD).
To get them, though, you’ll need to join YAYG (YET ANOTHER YAHOO GROUP).