Bookstore
http://www.cutdata.com/ This is an interesting website. Lots of machining data available here for 3750 materials, many tools and operations. You have to pay for the info here, but there is a trial version for free...try it. It's the best machining data I've found on the net.
http://brassbar.copper.org/alloy360/free-cutting.html This is interesting reading about free cutting brass CDA36000