Solar resource is fuel to solar power plants and local geography and climate determine their performance. Availability of reliable solar and meteorological data is the key information for effctive development and operation of solar power plants. The objective of solar resource potential mapping is to develop a knowledge base and make it available in the form of online data services, data ready-for-applications, GIS data, maps and expert studies for investors, consultants, project developers, operators or strategic decision makers in governmental bodies and transmission companies. Two approaches of measuring solar radiation are discussed in this paper: measurements by meteorological ground instruments and solar radiation models based on satellite and atmospheric data. Both approached have their pros and cons. Combination of both of them brings benefis and signifiantly decreases the uncertainty of data. In the previous decade the progress of solar resource utilisation was the domain of some European countries, Japan, and USA. Presently, fast development of commercial solar power sector requires data services in global coverage. Not only rich economies are responsive in changing global energy patterns. In this study, we introduce SolarGIS database and the approaches of how data can be used in the solar resource assessments. SolarGIS database, developed and operated by GeoModel Solar, is a unique source of data for solar energy applications. It contains historical and recent solar radiation, meteorological and geographic data covering almost entire World. We also present our applied methodology on solar resource country mapping and show results from various regions. We cover methodology of acquisition, validation and uncertainty of provided data, assessments on solar resource potential and photovoltaic power potential of the region and recommendations on solar resource applications.