Hey, I got a few more quick questions.

#1:
How do you spell dipthonghs?
I can't really find any site that explains it.

#2:
Is it true that most of the Japanese letters are signs for objects?
Are these pretty much the only signs you need to learn?

http://www.csse.monash.edu.au/~jwb/hiragana_b.jpg

Oh, and I'm aware that '' = voiced versions of other letters.