Where can i edit the Size of the Thumbs that are getting displayed?
When logged in as an admin you can access "Config" in the control bar.
If you scroll down the page you'll see Picture and Thumbnail Settings.
(Notice at the bottom of the page it says "(*) Fields marked with * must not be changed if you already have pictures in your gallery")
The thumb size can be changed after you have pics uploaded, but the existing thumbs will not be changed unless you use the re-size pictures utility to rebuild the thumbs.
Thing is.. I've found out that the resize utility not always works, sometimes it blow up the thumbnail, instead of remaking the thumbnail witht he original picture. THat means that the thumb's quality will be very bad.
The re-size utility always creats the thumb from the original.
Where some get confused, is which thumb size in config is which.
The 'Max dimension of a thumbnail *', is the one coppermine uses to actually make the thumb.
The 'Size of thumbnails in pixels', in the album view list, just sets the display size on the front page, and squeezes or stretches the thumb to fit, if it is a different size.