Welcome, Jimmy Boy.
My approach is to keep the POV tight and describe the fight from one person's perspective, or maybe two or three if it's a big battle. A few general pointers on what battle feels like:
Confusion. Nobody, including the commander, knows for sure what is going on. Soldiers can't see or hear much outside their immediate area, so they may not have any idea what's going on anywhere else. Men in the thick of the fight can't process much except what's in front of them, and men in quiet areas have very limited information and so might grow agitated as the fight wears on.
Noise. Noise and other sensations add up to assault your senses, adding to the confusion.
Fatigue. Battle usually comes after you have already conducted some strenuous activity: a long march, a river crossing, preparing your battlefield. Short sleep. Not enough food. You can't get enough rest beforehand, and you can't get enough air during the fight.
Fear. Some experienced soldiers can control the fear, especially after they know what to expect. Training can mitigate it somewhat. But soldiers who haven't been in battle before are more likely to be overcome by fear, to freeze or to make bad decisions because of it.
Anger. My personal experience the first time I realized those sorry SOBs were trying to kill me. I was pissed. Not blind with rage, but angry enough to be sure I'd be able to kill.
Unpredictability. Battles can go on for a long time, and it can seem as if nothing is happening until everything changes in a heartbeat. A line that was holding firm disintegrates. An area where nobody was is suddenly alive with enemy. Or the enemy that was fighting hard suddenly disappears.
I haven't looked at Van's LJ, but I'd bet beans to bullets you can find some good stuff there. And there are quite a few others on these boards who can give you some firsthand accounts as well. Feel free to narrow your questions until you have the answers you need.
Good luck!
HN
