Java Database Connectivity (JDBC)

Dear Pro.:
since i installed the JAVA SDK 1.4.0 till now, i still cannot figure out how to make JDBC driver wrok for me. i used oracle 8.1.7 and java SDK 1.4 to do my project on Windows 2000 professional platform.

i used the Oracle thin driver, which is in the directory D:\oracle\ora81\jdbc\lib\classes12.zip
and then i followed the instructions on "Oracle8i JDBC Developer's Guide and Reference Release 3(8.1.7)" to add a new user and system variable called CLASSPATH, and put the variable value
D:\oracle\ora81\jdbc\lib\classes12;D:\J2SDK_Forte\jdk1.4.0\lib;D:\J2SDK_Forte\forte4j\lib;
then i run the program, which is also in the "Oracle8i JDBC Developer's Guide and Reference Release 3(8.1.7)". but the error "package oracle.jdbc.driver does not exist" appear.

1. should i unzip the classes12.zip?
2. should i need to add a new CLASSPATH variable, or just use path variable which contains the "..\bin"? in either user or system section or both?
3. should i include the "D:\J2SDK_Forte\jdk1.4.0\lib" or "D:\J2SDK_Forte\forte4j\lib" in CLASSPATH variable?
4. what else should i do to make the JDBC driver work for me?

Thanks for your consulting in advanced