There is a component available that will make the necessary changes to migrate your core
content from Joomla 1.0.12 or 1.0.13 to Joomla 1.5.
It will also migrate data for third pary extensions by installing the Third Party Migrator plugins.
However you may still need to wait for your extension(s) to be available for 1.5 - check status at third party developer websites.
Follow the instructions carefully. Make sure you are backed up first. Don't remove you old install
until you are sure the migration was successful.

Click here to read about Joomla Migration and the Joomla 1.5 Migrator component

If you would like to purchase Joomla migration as a service please contact me for a quote.
The first stable version of Joomla 1.5 is available for download at

Now that Joomla 1.5 Stable is available you might be looking for a manual and some tutorial videos.

From the official Joomla site:

Joomla 1.0.13
"This release features several improvements to the password storage system designed to help protect the future security of your Joomla! powered website.  These changes will cause compatibility issues

SSL Secure Connection