What benefits does cow manure on a garden?????

I will be getting the bed of my truck loaded up w/ composted cow manure tomorrow from my uncles farm. How do I properly use it? We just moved into our home in October and finally the weather is allowing us to work the blank canvas. It has become over grown the last 6 years. It is 100' x 60'. Should that be enough? I know that is a tough ? to answer but any wisdom that can be shared would be awesome!

Here's an article that explains some benefits and also discusses precautions that are needed -

http://www.farmerfred.com/manures.htm

Composting of the manure is important. But some of the stuff sold by the big box stores, in my experience, has been leached to the point itnis no longer very effective. You're fortunate to have a source of the genuine stuff.

Yuska