[Xuande]

If you're just wanting to know simple short phrases then you shouldn't have too much trouble. Just find a good book and study up a bit.

Hello-Ohayoo Gozaimasu for mornings, Konnichiwa for afternoons, Konbanwa for nighttime, moshi moshi for answering the phone.
Goodbye-Jaa mata, Sayonara (used for when you're parting for a longer a period of time, like if you won't see them till the next day.)
Thank you-Domo would be like thanks, Arigatou is like thank you and Arigatou Gozaimasu is like a more formal thank you.
Yes-ee or hai
No-iie
I'm bored-I don't know

I'm sure that someone else could explain it all better. I believe that the thread Nihongo de Asobo has some useful phrases now that I think about it.