Photoshop Outsmarted Me Once Again, Help Please?

[Crashfan3]

I'm about to pull my freakin' hair out, although the answer's probably simple.

I have this image:

and this image:

I want to change the white parts of that first one to transparent and put it on the second image, but I can't figure out how! >.<"

I'm using some outdated version of Photoshop Elements (version 3.0 I think) that I got for free, because I don't have $750 to blow on CS3 or something like that.

Please help if you can. x.x