Do these mail well just wrapping them in paperback type paper?  I was going to saran wrap it first. 

That should say paperbag type paper.

I just sent 4 Harry Potter audio books (in cassettes)--there were a lot of tapes in each so the boxes were thick. I put them in a large bubble mailer--stuffed rolled plastic bags on each side of the box for cushioning--and then wrote DO NOT CRUSH on both front and back of mailer.

I would rather be safe than sorry as cassettes could easily be damaged in transit.

I was wondering this too... and if heat is a concern?

Thanks for the input :)

I mailed two audiobooks today.  One I put into a padded envelope (it had bubble wrap on the inside), and the other I wrapped in bubble wrap before I put it into an envelope.  I don't guess there's much I can do about heat.  But they were cds, which seem more sturdy than cassettes.