conditional formatting three columns or more

Hi, I am new to using conditional formatting and just installed excel 2010 and want to take advantage of this ability. However I can not figure out how to compare 3 cells and format based off contents. I have attached a real simple example probelm. I am applying this to compare bid results from numerous vendors.

I would like to apply the color yellow when a cell contains the lowest value compared to the other 2 cells in its row. Next apply green fill to cells who are second lowest value in the row.

How would the rules change as the number of values to compare increases? i.e. comparing 5 values across 1 row.

Thanks for the help