Ubuntu Jaunty has greatly improved default font settings. It uses FreeType 2 with a built-in autohinter and more advanced features. For most users there's nothing more to be done. On older versions of Ubuntu the default setup was not optimal. If you are using an older version of Ubuntu, see Johan Kiviniemi's tip for fixing font rendering on Ubuntu (he suggests that you should make this change on Ubuntu Jaunty as well).
Ubuntu's default system font is Bitstream's Vera Sans, which is called just Sans in Ubuntu's font list.
The system font can be changed in Preferences under Appearances on the Fonts tab. Some change the font to Deja Vu Sans, which is an extension of Vera Sans, with a wider range of characters. In the Synaptic Package Manager install ttf-dejavu and ttf-dejavu-extra.
Another popular option is to use Lucida Grande, the default system font on the Mac. Apple makes this font available for Windows when you install the Safari browser. It is not available for Linux, but you can install the Windows version by installing Safari using Wine on Linux (or by copying it from a Windows computer that has Safari installed). A close variation that's widely available is Lucida Sans, which is in the Sun Java fonts package (install sun-java6-fonts).
Luxi Sans is the default system font used in Red Hat's Bluecurve theme. The Luxi fonts are licensed under terms that are incompatible with the the Ubuntu Free Software guidelines. You can add them by installing ttf-xfree86-nonfree. Included in this package of fonts is the Liberation Sans font, which is designed to match Arial, the system font used in Windows.
Ubuntu does not provide a tool to let you view the fonts on your system. That's a big hole that needs to be filled. In the meantime you can add an application that will let you view all the fonts you have installed.
Go to the Synaptic Package Manager, which is in Administration under the System menu. In Quick Search enter specimen. Select gnome-specimen and click on Apply.
To start the font viewer, under the Applications menu, go to Graphics and select Specimen Font Previewer.
The Liberation Fonts are designed to be replacements for the three most commonly used fonts on Microsoft systems: Times New Roman, Arial, and Courier New. These fonts are metric-compatible with Arial, Times New Roman, and Courier New.
To add these fonts to your Ubuntu system go to the Synaptic Package Manager (from the System menu under Administration). In Quick Search enter liberation. Select ttf-liberation and click on Apply. These fonts are fully supported by Ubuntu.
Microsoft Core Web Fonts
Another set of fonts that can be added is the Microsoft Core Fonts for the Web. There were first released in 1996, with support ended in 2002. The fonts are included as standards in both Windows and Mac OS operating systems. The fonts included with the package are Andale Mono, Arial Black, Arial (Bold, Italic, Bold Italic), Comic Sans MS (Bold), Courier New (Bold, Italic, Bold Italic), Georgia (Bold, Italic, Bold Italic), Impact, Times New Roman (Bold, Italic, Bold Italic), Trebuchet (Bold, Italic, Bold Italic), Verdana (Bold, Italic, Bold Italic), Webdings. It does not include Tahoma or Arial Narrow
These are not free fonts but are legally available without charge. They are not supported by Ubuntu (meaning that if you have any problems you won't get help). They work just fine on Ubuntu and all other Linux systems.
To install them go to the Synaptic Package Manager (from the System menu under Administration). In Quick Search enter mstt. Select msttcorefonts and click on Apply.
You can add any TrueType font. There are a variety of sources for fonts. A type foundry like Bitstream sells a whole catalog of fonts. DaFont.com has a big collection of freeware and shareware fonts.
Fonts are added simply by dropping them into the appropriate folder. Systemwide fonts (fonts that are available for all users) should be put into /usr/share/fonts/truetype. That's for TrueType fonts only. There are other folders for Postscript fonts and fonts of other types.
For most users, you only need to add fonts for your own use. This means putting fonts into your own fonts folder.
From the Places menu on the top panel select the Home Folder. Under the View menu item check the box for Show Hidden Files. Then under file Name look for a folder named .fonts. It must have the dot (period) in front of the name. This folder may not exist. If you don't find it, create it; under the File menu select Create Folder, then enter the name .fonts.
Open the .fonts folder and put any TrueType font (a file with the extension of .ttf). The fonts become immediately available. However, if you have any applications open they will have to be restarted before you will have access to the new fonts.