Erin. Some excellent suggestions above in this thread. You can improve your ear a little by trying to pick out really, really simple tunes as well by yourself. I mean really simple, Twinkle Twinkle Little Star and other nursery rhymes. Then go for some of the extremely well known Christmas tunes. Even if you don't get the entire tune picked out by yourself, congratulate yourself for the three notes in a row that you did manage to find.

For tips about playing etc. you could also check out http://www.chiffandfipple.com/table2.html. Its a fun site.