Crystal Reports is an extremely powerful report creation tool, a single user version of the designer (version XI) is shipped with GoldMine 7 and PE , this allows you to build your own custom reports for use against your GoldMine database. However you can also use other data sources and even mix them together.
For example you might have an accounts system (Sage 50) and your customers are also in GoldMine, with a common customer ID stored against the GoldMine record you can report on data from GoldMine and Sage 50 at the same time.
Understanding crystal reports is not very difficult, some understanding on the GoldMine table structure and you can be racing ahead building some very pretty reports.
I can provide a training session that will help you get the most out of Crystal and your system, Even if you use another CRM system Crystal Reports could very well open up more reporting potential