This tutorial will show you how to add up Captions in English as well as native language to Youtube video or better adding a subtitle to Youtube video.This doesn't refers to any doc or something but i guess the first simplest tutorial on the web for this new feature without using any third party software.
Just follow the easy steps and you should be done.
1) Upload your video file to Youtube the one which you want to add captions/subtitle.
2) Create the subtitle files which will show up the text. To create the subtitle follow the following steps.
a) Create a next file. Name it anything as you like with any extension. Pref a .txt file or a .sub or.srt file. But it doesn't matters.
b) Now we shall put the text with time lines and say when to display and what to display.
Quoted from http://help.youtube.com
The supported format consists of text divided into separate caption (or subtitle) segments, in chronological order. Each caption must have three parts:
1. A timecode
2. The caption text
3. A blank line
Timecode: Specifies when the caption should be shown, and for how long.
Time is measured from the start of the video in these units:
* HH - Hours starting at 00
* MM - Minutes (00-59)
* SS - Seconds (00-59)
* FS - Fractional Seconds (0-999)
We support these timecode constructs:
* HH:MM:SS.FS,HH:MM:SS.FS - Caption display starts at the first time, and stops at the second time. This is compatible with the SubViewer format.
* HH:MM:SS,FS --> HH:MM:SS,FS - Caption display starts at the first time, and stops at the second time. For complete compatibility with the SubRip format, a 'subtitle number' can also precede this timecode.
* HH:MM:SS.FS - Caption display starts at this time, but no stop time is defined. We'll try to figure an appropriate stop time.
Caption text: One or more lines of text. This text must be UTF-8 encoded so that any language can be supported.
Blank line: A blank line is used to mark the end of each caption.
Example:
* 0:01:23.000,0:01:25.000
Text shown at 1 minute 23 seconds into the video, for 2 seconds
* 0:02:20.250,0:02:23.8
Text shown at 2 min 20.25 sec, until 2 min 23.8 sec
* 0:03:14.159
Text shown at 3 min 14.159 sec for an undefined length of time.
* 00:03:45,6 --> 00:03:47,6 Text shown at 3 minutes 45.6 seconds into the video, for 2 seconds, in SubRip format.
So basicically as a whole if you see this example video the caption that shows up has the following.
0:00:2.000,0:00:15.000
Hay Hi
0:00:16.000,0:00:30.000
This is the caption we have added
0:00:30.000,0:00:50.000
Ya its that easy to add.
0:00:51.000,0:1:11.000
You can try it your self.
0:1:12.025
Just visit http://classictutorials.blogspot.com and check out the simple tutorial.
Remember to save the file as UTF-8 or Uncode to support other regional languages. The above video also has a Hindi caption.
To write Hindi caption you can write your text in English and use Google translator and save the file as Unicode.
3) Now we shall upload the subtitle files. Click on Account--> Uploaded Videos -->The Video's Edit button --> Click on Captions and Subtitles. Remember to put proper name as Track Name because it will be shown to the user when the caption is clicked and will give an idea about the caption.
4) Once the upload is done it should ideally take 2 to 3hrs to show up the captions/subtitles on the youtube video.
Source: http://classictutorials.blogspot.com/2009/02/tutorial-for-adding-captionssubtitles.html | 
