Well you are reading it right now! This depends on what you want to achieve. If you are new to Joomla! and have no clue how it all fits together, just install the sample data. If you don't like the English sample data because you - for instance - speak Chinese, then leave it out.

Installing of Joomla! 1.5 is pretty easy. We assume you have set-up your Web site, and it is accessible with your browser.

Download Joomla! 1.5, unzip it and upload/copy the files into the directory you Web site points to, fire up your browser and enter your Web site address and the installation will start.

For full details on the installation processes check out the Installation Manual on the Joomla! Help Site where you will also find download instructions for a PDF version too.

Joomla! 1.5 does not provide an upgrade path from earlier versions. Converting an older site to a Joomla! 1.5 site requires creation of a new empty site using Joomla! 1.5 and then populating the new site with the content from the old site. This migration of content is not a one-to-one process and involves conversions and modifications to the content dump.

There are two ways to perform the migration:

The collation option determines the way ordering in the database is done. In languages that use special characters, for instance the German umlaut, the database collation determines the sorting order. If you don't know which collation you need, select the "utf8_general_ci" as most languages use this. The other collations listed are exceptions in regards to the general collation. If your language is not listed in the list of collations it most likely means that "utf8_general_ci is suitable.

This is now implemented by inserting a Read more... tag (the button is located below the editor area) a dotted line appears in the edited text showing the split location for the Read more.... A new Plugin takes care of the rest.

It is worth mentioning that this does not have a negative effect on migrated data from older sites. The new implementation is fully backward compatible.