A good classic text is Soil Testing for Engineers, by T. William Lambe. It is old, but its concepts and information are timeless.
Another good classic text is Engineering Properties of Soils and their Measurement, by Joseph Bowles.
There are several others that are later and perhaps have a few updated standards references, but you find a better treatment of the subject than these two.
Both are still available through Amazon. Google them if you want the ISBN numbers.