How do I cut images then enlarge and transfer to another image on GIMP?

[0tt3rL0rd]

I am attempting to cut a piece of an image from a photo then enlarge it then transfer it to another photo and I am wondering how to do this. I have attempted the Alpha Channel and Mask stuff but that's not working for the image will be several times larger than it is on the screen and either with a white background or it will be completely see-through. Any real assistance would be greatly appreciated. Thanks.

[Jonor]

To cut a piece use a select tool such as the rectangle select.
Mouse clicking on the selected rectangle will remove everything else.
Enlarge with Image > Scale Image.
Use Edit > Copy Visible to copy to the clipboard.
The last part is Edit > Paste Into to add to another photo, space must be made for the new piece beforehand.
This last step will take a while to understand, but comes with practice.

[Buntu Bunny]

Alternatively you can erase the parts of the image you don't want.
With the image open, select the "Layers" tab of the "Layers, Channels, Paths, Undo" tabs of "Toolbox - Tool Options."
Right click that box and select "Add Alpha Channel"
The eraser tool will now erase to a transparent background.
You can enlarge as Jonor said, copy, and paste to your destination.