Starting on a completely new translation

So you want Skype in your language too? Yes, that can be done, though if it's not a really big language, Skype itself won't host it, you will have to point people here for the language file or some other site where you keep the file. It take time but it's not hard. Here's what you do (assuming you're working off English but you could also work from another language, like Russian):

1. Make some coffee

• Go to Tools > Change Language > Edit Skype Language File
• The first thing to do is to save the current language file under a different name. Let's say you want to translate into Navajo. Click on Save as and call it (for example) Navajo.lang
• Now you have two choices. You can translate within Skype. If you're doing that, put your translations into the Current column. Don't forget to save frequently. If you hit the Apply button it will start showing what you've done so far in the program. It's a good idea to check now and then to make sure you're doing ok, rather than spending 5 hours translating and the spotting a problem saving files or something.
• You can also translate offline. Just open the Navajo.lang file in a text editor like Notepad++ and put your translations BEHIND the = signs. Don't mess with the "code" in front of the =, that's just for Skype to recognize which string goes where.
• That's it. You can then send the file to people (and maybe to us too) or host it somewhere else so people can find it.

Tips, tricks and some good advice

• When you see the & symbol, that*s a hotkey. For example there's &Help in the English file. It means that when someone is using English, they can get to Help by pressing ALT+H. If your language uses and alphabet, you can also do that but it's best to avoid accented letters (like á é ù ü and so on) unless they physically appear on your keyboard. If you don't have an alphabet, it's probably best to just leave them out.
• When you see %s, that's a placeholder. For example, Call from %s will show up as Call from Pierce Brosnan so you have to use the %s in your translation somewhere.
• When you see stuff in <> brackets, that's formatting and stuff. For example, makes stuff bold. You also need to retain those in your translation, around the appropriate words.
• Changing the order, plurals and other fancy stuff - I'm afraid not. Skype is a bit stone age when it comes to things like that.

Oh, and a last piece of advice. Prioritize. It's a fairly big file and will take time. I would recommend you focus on the most visible bits first. No one ever reads the EULA anyway ;)