11g comes with quite a number of demo schemas (seeded tables which can be queried to understand /Learn various SQL commands). To know more about it, go to: Download Oracle Schema
Scott User which used to come unlocked and OPEN in every version, is no longer the case. You need to manually unlock the user. To learn more about SCOTT Schema go to: http://wiki.oracle.com/page/scott%2Ftiger
To learn about installing Sample schemas in 10g, go to :- Installing Sample Schema's
Sample Schemas reside under $ORACLE_HOME/demo/schema. Demobld.sql resides under $ORACLE_HOME/sqlplus/demo
