The Russo-Japanese war (which I wrote a paper on last year) is often considered the first modern war, it had the largest (to that time) land battle in all of military history at Mukden.
Although I could explain all the battles and campaigns I think it would be more reliable if I directed you to a website written by actuall proffesionals.
http://www.russojapanesewar.com/intro.html
For helping ot end this war Teddy Roosevelt (the man!) got the Nobel Peave Prize, what an ironic person to get such an award!