Material Editing Issue

Hi, I'm pretty new to Irender and love it so far.  As I get farther into the modeling, I'm noticing some weird things that I know is something I'm doing wrong.  I was using the CMU materials, and when I render the material...everything looks fine.  Now, I need it to be a certain color...so I open the material editor...click advanced...and change both the base and grout RGB's to match my desired color.  When I render the image...the color looks great...but then the material is now like 2x's bigger.  I try to change the scale under the advanced tab and that doesn't help either.  i am attaching an image to show you what I mean.  I copied the 2 materials on the right and painted the copied material to the left (this way when I changed the color it only changed the left side). 

Another question I had, was has anyone put together a PDF or something listing best settings for each material?  I was wondering because it would be nice to be able to look up the settings for split face CMU, marble countertop, hardwood floors, paint on walls...and so on.  So far I just have to trial and error it...but thought I would check to see if people have found a great setting they would like to share.  We could compile them all in one post or make into a PDF to put on the website possibly.  Just a thought...