HOW TO FANSUB DRAMAS?

If you have a copy of the raw media file you want to sub you can use a program like Aegisub to write your script and time the dialog to the file. Once you have the script/timing complete you can either mux the two together to make a single subbed file or leave them separate (though this normally defeats the purpose of subbing a file). A good muxing program is MediaCoder (free and has an active online help forum). If you're good enough you could apply to work with a fansub group. They would require you to take a form of test to determine your usefulness to them. But considering your stated inability to read Chinese it seems unlikely they could use you as a translator.