Regional data access is currently provided through NCI's THREDDS server.
Data are supplied in ESA's SENTINEL-SAFE format in zip archive and organized in a simple directory structure which divides the data files spatially and temporally, along with metadata for each zip file.
Client-side code to facilitate search and access has been contributed by the user community, including a Python command line tool that allows the user to search the server by date range, geographic region, and restricting by sensor-specific attributes. Details of this can be found at http://auscophub.readthedocs.org.
Specifications for SAFE file formats can be found in the User Guides for Sentinel-1, Sentinel-2 and Sentinel-3. Information about acquisition modes and data products can be found at Sentinel Online. Please check the User Guides for more details.
Open source toolboxes for visualisation, analysis and processing of the Sentinel data can be downloaded from ESA's Science Toolbox Exploitation Platform.