First and foremost Congratulations!
Here are some suggestions for getting started.
You will get your permit to report package sometime towards the middle of April. In the package will be full details of things you will need to do. There will be information that has to be sent back to USNA prior to IDay and information as to how to report. As far as what to bring - the Academy will give you instructions - (many on this board: parents, BGO's, Mids and Alumni will tell you to either ignore what the Academy recommends or they will tell you to follow the directions to the letter - that advice I will let you sort out)
As far as the background check - our area did not charge.
Information about Plebe summer can be found on many of the Parent's club sites and Alumni/Foundation site. Things change from year to year so read all the information as if it is a guideline only and not cast in concrete.
Here are some sites with good information:
This one will change as information form USNA becomes available: http://www.usna.edu/PlebeSummer/
Alumni and Foundation, there information is intended for Parents but you can learn some things too: https://www.usna.com/SSLPage.aspx?pid=415
and the survival guide: http://www.usna.com/Document.Doc?&id=220
On the Georgia Parents Club website http://www.usnapcga.org/
if you go to the downloads page there is some Plebe information.
These are some other sources that you can check out.
I know it is exciting to know where you will be going next year. Stay in shape. In the permit to report there will be a suggestion for a workout schedule prior to IDAY. Enjoy your friends, continue to study, stay safe physically and keep from doing anything that would jeopardize your appointment.