can I select what is stored on the iCloud ?

One thing you can do is to import your photos to your computer and delete them from your phone (see http://support.apple.com/kb/HT4083), then put them in a folder (or iPhoto event) and sync them back to your phone by selecting the folder (or iPhoto event) on the Photos tab of your iTunes sync settings and syncing your phone. This will put the photos in an album called Photo Library, which is not included in the iCloud backup (since they are already backed up on your computer), thereby reducing your iCloud storage accordingly.

Other suggestions are shown in this article: http://support.apple.com/kb/ht4847.

Thank you! This helped me too!