Well I was planning on having someone build a retaining wall for me in my home. You see I have a small New England Cape set up on a hill and the left side of my yard slopes drastically. Imagine if you look at the left side of the house there is app. 6 feet of exposed concrete foundation and this tapers half the distance of the house to the front steps. A guy came by the house and did an estimate for a wall that starts at five feet and tapers to 1 foot. I think he was planning on having the wall curve as well. If I ballparked the distance of the curve it would be about 20 ft. max. Anyway, he was going to make the wall out of faux stone, like concrete blocks and the estimate was too high for me...($6,000). In the mean time I have discovered a limitless source of FREE brownstone the same as was used to build many buildings in NY (most of brooklyn) and the Boston area. Here is an example of a wall in Hartford, CT made from the same stone...

http://www.brownstonequarry.com/pic9.htm

I was wondering how I would go about calculating total material needed?

If the wall tapers like I described above can I build it higher than 3' on one end, say 5'?

I was told for a 5' or 6' dry stacked wall I would need to go back 3'?

What are the rules for hieght to width relations?

Do I need to slant the wall into the hill?

Do I backfill with crushed stone?

How deep below grade do I start?

Mainly to start I would need an idea of how much stone to get, because my window of time is narrow, before all the free stone is gone. I plan on spending two days making trips with the pick up truck, but it will be very labor intensive and I do not want to come up short.

Sorry for the long post and thanks in advance for responses!