"Up & Down" : My first track

Hi guys,
I'm new to the community and look forward to being part of the DJTT community!

I saw this community and thought i'd past the first track i made, even though I know it's not worth a lot.
I composed it using samples from soundstosample.com, on INTUA Beatmaker on iPhone 4.

here it is:
http://soundcloud.com/freshfruitjuice/up-down-d-s-m-i-t-original-mix

Any tips and tricks which i can use to make a smoother sounding song ?
(I will from now on be using Garageband)

Thanks !