My first uniform book was a coloring book about the American Revolution. But perhaps the strongest effect were the uniform plates Tony Wold did for the book "The Book of History", part of a series of children books done in many languages . This was written by Giuseppe Zanini and we had the greek version. It was a joy of a book, and together with the series "The Ancient Peoples", probably made me a bookworm. One of my favorite things were the full page uniform plates. These got me interested in uniforms and down the way into military history, military figurines, and in the end wargaming. Here are the full page plates (click for larger picture).
I have a soft spot for the rules systems of the Two Fat Lardies. Perhaps the best fun for my money I ever got was the combination of Kiss me Hardy with Valiant 1:2000 Napoleonic Ships. Lots of fun was had. I am aware of the rest of their rule systems as well, but it never happened that I wanted to do a period that was covered by them. The exception was WW1, and I tried to steer Mehemt towards using the systems created by the Two Fat Lardies for it, but Mehmet decided he wanted to try his had at rules design. This is totally defensible, and a good decision, and the resulting rules "Trial by Fire" are worth a look. The second chance has been World War 2.