Q: Once I have loaded my photos on I cloud Can I delete them off my I Phone to fee up memory

You could but you're taking a chance on losing them if you do.  Photo stream photos only remain in iCloud for 30 days.  If you ever lose your phone, have to restore it, replace it, or turn off photo stream, you will only get back photos from the last 30 days.

To make sure your photos are safely backed up, import them to your computer while they are in the camera roll, as explained here: http://support.apple.com/kb/HT4083.  You will get an option to delete them from your phone after importing them.