It has been frustrating me so much and I just can't figure it out at all so I need a little help.

I have the sync installed for my Q9c and everything but I just don't know how I can download apps and such to my computer and then transfer it to my phone through syncing it. For instants, I downloaded a home screen off of one of the forms on here, I tried extracting the files, but I didn't know where to put them so they would sync to my phone.
Now I don't know if I'm going about this the totally wrong way or if I'm just making it harder then it is, but I am about to go nuts trying to figure this all out.
A little help please? I beg.
Thanks
Emily.