I tried searching her ebut didn't find anything so I went out and found this thougth I'd drop it inthe refferal section for future knowledge in case anyone else would like to know more about R value.
http://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table
Good solid guidelines and easy to understand. Thanks!
(http://i1.tinypic.com/mim32x.png)