transfer photos from Samsung mobile to computer

Welcome davyjean!
When you plug in your device into the computer, the drivers should auto install, then you can select, I believe, as a camera (ptp), or even a media device (mtp), and see the contents of your DCIM (camera) folder.
From there you can copy them to a folder on your desktop and upload them to Picasa.
I have not done that personally, but that is my best educated guess
Hope that helps a little bit and thanks for joining!