how is my singing and how can i improve?

how is my singing and how can i improve my voice(s) range and tone,
and just overall things i need work on, i all ways wanted to be a
singer, ive thought about americas got talent and american idol but
i'll prolly just be a little wedding singer to make a few bucks,

http://www.youtube.com/watch?v=GBRstglIXNE

this one is a newer one i did earlier this month

http://www.youtube.com/watch?v=LuPOtGjyscIfeature=related

this one is a while back

can you tell me if there's a difference in the songs like if my voice
has matured