I don't quite understand what you mean by picture in iPhoto called resources, but I'll give it a stab:
1. Create a Smart Album, and set the rule to be any picture that isn't called resources.
That should create a set of photos that are not the ones you wish to avoid.
2. Select all the photos inside this Smart Album.
3. Go to File->Export in the menubar and choose to export those photos into a new folder you will create on the desktop or directly on the thumb drive. Be aware that if you put the folder on the desktop you are making a (temporary) duplicate of ALL the photos in that album, so be sure you have PLENTY of disk space before proceeding! You can then copy the new folder onto the thumb drive and throw away the one on the original after its copied.
4. If you choose to export the pictures directly to the thumb drive, you don't have to worry about creating a duplicate set on your computer, but you should be confident before you start that the thumb drive will hold ALL the photos from your Smart Album.