I will edit this post little by little, and make it as one-stop guide for common font issues in Myanmar. I hope we don't need to answer the same question again and again on FB groups, blogs, Myanmar forums, etc.
I. How many kinds of Myanmmar fonts are there?
Four as far as I know
1. Unicode
2. Ayar - Unicode, but encoding is slightly modified
3. Zawgyi - Non-Unicode
4. ASCII - Winn Innwa
II. How to installl Unicode fonts?
If you're using Ubuntu 12.10 (Quantal), you don't need to install Unicode fonts. It's already included in Ubuntu. You can find it in the package Fonts-sil-padauk.
If you're using Ubuntu 12.04 (Precise) or later versions, you can still install Fonts-sil-padauk from the Ubuntu Software center, Terminal or Synaptic Package Manager.
Other Unicode Fonts ???
You can find other unicode fonts in
Code:
http://www.myanmarlanguage.org/unicode/myanmar-fonts-which-follow-unicode-rules
Ethnic Unicode Fonts
Tharlon supports some ethnic languages
There are other unicode fonts too. I'll add later.
III. How to install Zawgyi and other Truetype fonts (.ttf)?
Download Zawgyi 2008 from google code
Code:
http://code.google.com/p/zawgyi-keyboard/downloads/detail?name=ZawgyiOne2008.ttf
Double-click to open it. It'll open the Font Viewer.
Click Install.
### Should I install Zawgyi 2009?
No. Zawgyi 2009 is incomplete font. Though you can install it in Ubuntu, font may be displayed differently. Windows 8 even detects it as a corrupted font. And most people use Zawgyi 2008.
### What happended if I click Install in Font Viewer?
In 12.10 (Quantal), the font is installed tp ~/.local/share/fonts directory.
In 12.04 (Precise), the font is installed to ~/.fonts directory.
### Where is ~/.local/share/fonts?
Dot files/folders ( . ) are hidden in the HOME folder.
Open Home folder. Click Menu » View » Show Hidden Files.
Open .local » share » fonts
There, you'll see ZawgyiOne2008.ttf
In Precise (12.04),
Open HOME folder
Open .fonts folder
There, you'll see ZawgyiOne2008.ttf
IV. How to install multiple fonts?
Copy and paste the fonts to ~/.local/share/fonts OR .fonts directory.
If you can't find the folders, you'll need to create it yourself.
How to create a new folder ?
Right click >> Create New Folder
V. Problems, Problems that everyone thinks
Though there is Unicode font preinstalled and most of the unicode fonts are supported in many Ubuntu Applications, many people still want to use Zawgyi for personal reasons.
Common Problems in Quantal (12.10)
Though I installed Zawgyi, fonts are incorrectly displayed in Title bar of Firefox.

Or even worse, Facebook friends' names, page names or group names appear like this.

So, what's wrong here?
Nothing.
It's not the Ubuntu problem. It's the configuration problem.
Let's start with the Facebook problem first.
Ubuntu 12.10 has Unicode (Padauk font) preinstalled.
When you install Zawgyi, Zawgyi overides the Padauk font because it has more encoding points.
But ...., Zawgyi is incomplete.
If you analyse it more, you'll see that the place where Zawgyi doesn't appear are using Bold fonts.
Padauk is replacing these places instead of Zawgyi.
Why? Simple, because it is better.
OK. How to solve it?
Remove Padauk ??? --- A very bad idea. Why remove when it becomes default?
The solution -- Change Font Settings in Firefox
In Firefox, click on Menu » Edit » Preferences
A new window will appear.
Click Content
Click Advanced in Fonts & Color
You'll see Fonts for Western & a list of settings.
Click Western in Fonts for
Choose Other Languages
You'll see ( Proportional, Serif, San-serif, MonoSpace & their fonts)
Change the Serif font to Zawgyi One.
Click OK.
Close the Firefox Preference Windows.
Now, you can see Facebook Names in Zawgyi properly.
Problems in Chrome and Chromium ??
In Chrome/Chromium, Zawgyi replaces Padauk completely, so you don't need to change anything if you did like most people did.
If something is not right,
Type chrome://chrome/settings/fonts in the URL bar
Change the Sans-serif font to Zawgyi-One or the font you used.
Title Bar Fonts .... To be continued