Gems are basically divided into three catagories by the GIA for purposes of clarity grading. Type I, type II and type III.
I will quote from the GIA Colored Stone Grading Workbook.
Type I Colored Stones (Often virtually inclusion-free).
Type II Colored Stones (Usually Included).
Type III Colored Stones (Almost always included).
As you can see, a type I colored stone VVS grade is eye clean with inclusions that are difficult to see under 10x magnification and invisible to the unaided eye, while a type III VVS has inclusions that are easy to see under 10x magnification and may have eye visible inclusions.
What's a poor rookie to do?
Well one thing to do is to understand the above scales and which stones are in which category. Do NOT be surprised if your local retailer does not know each stone in every category, or even what you are talking about!
Do understand that if your local retailer
does not have at least a fair understanding of which stones should normally be
eye clean, and which stones are still beautiful even with fair amounts of eye
visible inclusions, that you should probably be looking for a different local
retailer if you are in the market for a good buy on a colored stone.