A saga from an experienced Firebird user new to Linux:

Ok, I went to www.firebirdsql.org to get a recent package to install on
Ubuntu Desktop. Found FirebirdCS-2.1.1.17910-0.i686.tar.gz and
downloaded it. Unpacked it into a directory and looked inside. Found
install.sh but wasn't sure what to do with it. Decided to get some
documentation. Went back to www.firebirdsql.org to the documentation
page. Found Quick Start Guide. Looked at installation section which says
to be sure to check the release notes for important details. No other
details on installation procedures are in the Quick Start Guide that I
could find.

From Quick Start Guide:
"In all cases, read the Release Notes that came with your Firebird
package (chapter Installation Notes, section
Posix Platforms). There may be significant variations from release to
release of any Posix operating system,
especially the open source ones."

I looked in the 2.1 Release Notes pdf and there is no Installation Notes
section that I could find!

"For Linux distributions that cannot process rpm programs, and for Unix
flavours for which no .rpm kit is
provided, use the .tar.gz kit. You will find detailed instructions in
the Release Notes."

Cannot find these!

Where have I gone wrong?

What I actually want to know is step by step how to install and
configure on a Ubuntu Server using only the command line.