After you downloaded CUBRID files from http://www.cubrid.org/downloads, here are detailed documentation you can refer to. 

Tutorials

If you are new, you can get started with these tutorials which cover How to install and to build, Configurations, Development tips, Admistration tips and CUBRID Architecture and concepts.

http://www.cubrid.org/tutorials

Manual References

CUBRID Manuals is a superset of tutorials. They consist of chapters as following: Introduction, Getting Started, CSQL Interpreter, CUBRID SQL guide, Administration guide, Performance tuning, API references, and CUBRID Manager guide.

http://www.cubrid.org/manuals

Release Notes

If you consider version updates or look for new features and fixed bugs of a specific version, you'd better to read CUBRID release notes. The link also contains QA test reports having perfermance comparison between the latest version and the previous version.

http://www.cubrid.org/release_notes

Wiki Articles

CUBRID wiki pages are for collaboration and instant documentation of CUBRID Tools and Drivers projects. They contains specification documents, change note(or release note), and unit test results.

http://www.cubrid.org/wiki_tools

http://www.cubrid.org/wiki_apis

http://www.cubrid.org/wiki_tutorials

http://www.cubrid.org/wiki_apps

Video Trainings

CUBRID provides video tutorials for your first step to CUBRID. They contain How to use CUBRID Manager to create DBs and Tables, and to execute SQLs.

http://www.cubrid.org/video_trainings

Other Resources

CUBRID Blog covers various topics of technical articles including trendy news, NoSQL, database or storage related articles, and other opensource products.

http://blog.cubrid.org/

Latest Tutorials

CUBRID Tutorials

It is very easy to get started with CUBRID. Follow these step-by-step tutorials and you will see how fun it is to learn CUBRID.

CUBRID Tools Wiki

There are GUI based tools to manage CUBRID.
CUBRID Manager (CM) is the most powerful database administration tool for DBAs and Developers.
CUBRID Query Browser (CQB) is a light-weight SQL execution tool for developers.
CUBRID Web Manager (CWM) is a PHPMyAdmin like tool which is embedded in CUBRID Engine Package. After installation CUBRID Engine, just open https://localhost:8282 in your browser.
CUBRID Migration Tool (CMT) is a batch data migration/export tool from other DBs to CUBRID and to dump files in a format of *xls, *.sql, *csv based on your reserved schedule.

CUBRID APIs Wiki

There are many of drivers(connectors) that you can use. Pick up a right one and develop your application with CUBRID. Visit these online resources and read our documentation.

Getting Help

If you still have questions, do not hesitate to post them to @cubrid Twitter, CUBRID Facebook wall, or to CUBRID Forum

Visit these online resources and read our documentation at http://www.cubrid.org/tutorials.