If you planned an extended stay in another country, how soon would you start to learn the language? How would you go about it?

As soon as I make the decision!

depends on how much time I have before departure,If it's sufficient then I learn it by the Internet,softwares and etc..basically I'll learn it on my own.

but if I'm in a hurry then I'll probably take a class or hire a tutor.

I am absolutely helpless when it comes to learning another language. I've tried but a week later, I forget all that I've learned. Now, I have an app on my phone that I can speak into and it will repeat in the language selected.

If I knew ahead of time I would start learning before I left through a program like Rosette Stone.  Even for short visits I learn few basic things before I leave. Things like please, thank you and "Where is the bathroom?"

One year.

I'd just plan an extended stay in an English speaking country! :)

immediatly i would learn the basic greetings first and take it from there

If I'm staying there for two years, I'd start after a few months. So far, the only foreign language I've learned is Urdu. Love cursing people who I hate in that language. I also have a really good friend in Pakistan so that's kinda why I learned it.