D.W.
I have a NoJo padded ring sling, non-structured wrap, baby bjorn and an ergo. The NoJo and Wrap were probably the easiest to breastfeed a newborn in, for a larger baby - the ergo.
Some good articles:
http://www.mothering.com/green-living/babywearing-tips
http://kellymom.com/parenting/sling.html
You really do need to try a few and see which feels best to you. A lot of times you can find them for a good deal at a second hand children's shop.
Good luck. My baby girl lived in her sling the first year, and we went everywhere. Enjoy!