i See, i Touch

So, I consider myself one of the tech-challenged kids in my class.  But I impressed myself yesterday by charging my iTouch on my laptop and setting up my email.  This might not seem like much of an accomplishment, but I was glad to have made it that far.
I have not attempted to download any applications or applets yet.  I am not sure how to go about that.  I have iTunes and I think I was able to sync my touch to my computer.  Perhaps we could walk through one in class?
Regarding the apps you have to pay for, is there a 3-day trial where you can return if you don't like the product?  Is there a way to test an app before buying?  I guess I can forsee someone buying lots of apps because they are relatively cheap, but if they are not helpful or if you never use them, then why keep them.  Oh, right, you paid 99 cents for it. 

Thanks to our Professor for bearing with the slow ones in the group.  I think you have convinced us all of the merit of technology, but some of us may still need some hand-holding from time to time.