The universe is vast. This we all know. This basic knowledge of the galaxy as we know it also applies a long time ago in a galaxy far, far away..
1. Where Tatooine, Hoth, and all those planets are located?
2. what languages they speak and what is the common intergalactic language used to communicate between species in the Star Wars universe?
First question first, here's Star Wars - The Essential Atlas.. it will guide you there in no time at all :) Download from the link and you'll get something like this:
"And what about they're languages??", you ask.. well, seek and you shall find in the wondrous WWW. Go here for guides of whatever language they speak in each planet (well, not all planets.. the famous ones, anyway): http://en.wikipedia.org/wiki/Languages_in_Star_Wars
..not sure if this is the most accurate source, though.
Anyway, the one common language they use to speak and write (which is kind of like the English language is used as the international language here on Earth), is called Aurabesh.
Unless you just bought yourself a C3PO protocol droids that speaks 6.000.000 dialects, then you'll be needing this:
I've given you all that is required for a safe and enjoyable intergalactic travel to the Star Wars galaxy. Just make sure you don't meet space pirates along the way :)
Have fun writing in Aurabesh, Masters..
Donny a.k.a Master DJ Yoda