The improved Installer can be found under the Extensions Menu. With versions prior to Joomla! 1.5 you needed to select a specific Extension type when you wanted to install it and use the Installer associated with it, with Joomla! 1.5 you just select the Extension you want to upload, and click on install. The Installer will do all the hard work for you.

You indeed can change the Menu Item's Type to whatever you want, even after they have been created.

If, for instance, you want to change the Blog Section of a Menu link, go to the Control Panel->Menus Menu->[menuname]->Menu Item Manager and edit the Menu Item. Select the Change Type button and choose the new style of Menu Item Type from the available list. Thereafter, alter the Details and Parameters to reconfigure the display for the new selection as you require it.

Yes! Prior to Joomla! 1.5, only the text values of an Article and only for ISO-8859-1 encoding was allowed in the PDF rendition. With the new PDF library in place, the complete Article including images is rendered and applied to the PDF. The PDF generator also handles the UTF-8 texts and can handle any character sets from any language. The appropriate fonts must be installed but this is done automatically during a language pack installation.

Most Articles will be assigned to a Section and Category. In many cases, you might not know where you want it to appear so put the Article in the Uncategorized Section/Category. The Articles marked as Uncategorized are handled as static content.

In Joomla! versions prior to 1.5 there were separate processes for creating a Static Content Item and normal Content Items. The processes have been combined now and whilst both content types are still around they are renamed as Articles for Content Items and Uncategorized Articles for Static Content Items.

If you want to create a static item, create a new Article in the same way as for standard content and rather than relating this to a particular Section and Category just select Uncategorized as the option in the Section and Category drop down lists.

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.

Within the Installer you will find a wide collection of languages. The installer currently supports the following languages: Arabic, Bulgarian, Bengali, Czech, Danish, German, Greek, English, Spanish, Finnish, French, Hebrew, Devanagari(India), Croatian(Croatia), Magyar (Hungary), Italian, Malay, Norwegian bokmal, Dutch, Portuguese(Brasil), Portugues(Portugal), Romanian, Russian, Serbian, Svenska, Thai and more are being added all the time.
By default the English language is installed for the Back and Front-ends. You can download additional language files from the Joomla!Extensions Directory.

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.

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.

Got a question? With more than 210,000 members, the Joomla! Discussion Forums at forum.joomla.org are a great resource for both new and experienced users. Ask your toughest questions the community is waiting to see what you'll do with your Joomla! site.

Do you want to show off your new Joomla! Web site? Visit the Site Showcase section of our forum.

Do you want to contribute?

If you think working with Joomla is fun, wait until you start working on it. We're passionate about helping Joomla users become contributors. There are many ways you can help Joomla's development:

• Submit news about Joomla. We syndicate Joomla-related news on JoomlaConnect^TM. If you have Joomla news that you would like to share with the community, find out how to get connected here.
• Report bugs and request features in our trackers. Please read Reporting Bugs, for details on how we like our bug reports served up
• Submit patches for new and/or fixed behaviour. Please read Submitting Patches, for details on how to submit a patch.
• Join the developer forums and share your ideas for how to improve Joomla. We're always open to suggestions, although we're likely to be sceptical of large-scale suggestions without some code to back it up.
• Join any of the Joomla Working Groups and bring your personal expertise to the Joomla community. 

These are just a few ways you can contribute. See Contribute to Joomla for many more ways.