The first one is giving the overall U-Values for the building materials. I think their units are metric (W/(m2.K)). And its saying that overall U-Value is reciprocal of sum of all the R-Values of wall/roof assembly.
The second one is showing the relation between R-Value and k-value. How one can obtain the R value from the k value.
Now its sometimes confusing. You have to understand each one
1. Thermal Conductivity - k value - Unit is W/(m.K)
2. Thermal Resistance - R Value - Unit is m2.k/W
it can be obtained from k-Value with the formula described in Wiki Answers
for a Wall(or roof) assembly made of different layers, first thing is to determine individual R-values of each layer. then compute total resistance Rt as
Rt = R1+R2+R3+....
Now U-Value is the reciprocal of Rt (U = 1/Rt)
U value is called overall overall heat transfer coefficient
its units are W/(m2.K)