Hi Elison,
I warmly recommend Harry Lorayne's books, a long time ago when I was 10 years I read "How to develop a super power memory", and while I don't have a super power memory, I have at least a fairly good memory, especially when I use his methods. You may also take a look at his newer memory books based on the same technique, but feeling more modern. The book I read is from the 60's, so while the technique is more or less the same, it now feels a bit out fashioned.
Tony Buzan's books are also good, I have them, but haven't found time to read them thouroghly yet.
Good luck!