Here's a link that I hope would be helpful:
http://www.fda.gov/fdac/features/2000/300_soy.html
I eat meat, but am not that big on red meat. My meat sources are usually chicken breast and fish. However, like most everyone, there aren't enough hours in the day for me to prepare lean meat, so this is where dairy comes in. I'm lactose intolerant and drink a lot of soy milk. I can use regular milk in its different forms (condensed, evaporated, skim, etc...) in small amounts, but drinking glasses of it greatly upsets my stomach. Small amounts of cheese is also okay.
Like the article says, soy isn't magic food and every health claim has its differing schools of thought. I hate to be redundant but you do have to see if soy works for you as every body is different.

If you have a reaction to it, it might pay to talk to your doctor about it and avoid soy altogether. I love certain vegetables, but some of them, like asparagus and broccoli, when I eat too much of them, can do a number on me.
I've gained a pretty decent amount of muscle with lots of soy, lean chicken, fish, egg whites and low fat dairy. It's a combination of all these foods that helped me, not just soy alone.
Pinky
Editing to add that whey protein has also helped.
