editing pictures  

you can use a program called gimp to crop the image the resize it, i advise taking in raw format then you wont lose much quality!

Picture Manager is mainly a viewer, not an editor, therefore you'll want to actually use a different program for changing pictures.

Often your printer will come with photo-editing software. Check for programs under the printer manufacturer's name (i.e. HP, Dell, Canon)

Once you find one, you should be able to crop and edit pictures and save them. Note that cropping does not zoom, but simply makes the picture smaller. Some programs have a zoom feature, but with many you have to adjust the image size in order to zoom in.

If you find a picture editing software and let me know the name of it I can probably give you better instructions.