Then, the thing with short and long vowels.
what do you write if you want to say "ba" ? with short a?
بَ is the answer. You take "b" and add a short line above it, which gives it a short a sound.
What about "baa" then, with long aa?
بــا is the answer. you don't have to add the short line above b, as it's followed by alif, which gives it long aa.
So, how would you write babaa ?
if you are thinking of بَـبـا, you're right!
Let's change vowel now. How would you write "bi" ?
بِ is the answer. Yes. It looks like ba, but the short line is under the letter. it gives it a short i sound.
and for long bii.. the rule is same as with baa..
بــي
just take b and add "y". it gives the b long ii sound.
And finally, u. The vowel mark for u is short waw, و above the letter.
bu = بُ. And for long buu, just take b and add waw (و).
بـو buu.
Clear?
Yessss very very clear 
thanks I think I am getting used to these vowels now.