I'm very un-computer inclined, but was noticing about half my memory (4.4 GB of 8) and half my ram (321 mb of 7) are bing used. I don't think there is anything on my SD. How do I use it properly? What things I should store on the SD? is there a good app that does it automatically, or do I need to move things? if I do need to manually move them, how it that done? Any help with these rudimentary questions are very much appreciated.