My favorite singer is Declan Gailbraith.

He is really a great singer, and he showed his talent when he was only 8 years old. The song "tell me why" shook me,and when I heard "an angel",  I was really fascinated. His voice was so wonderful. There are many fans of him in China, they call themselves "December",and they all crazy about him. Declan was born in december of 1991, the same year and month as me. Although his voice has changed, it's not as sweet as it initially was,but it is still attractive. He had a concert in China in 2008,and his news is infrequent recently. I hope he can give more beautiful songs to us.

Okay! Not a bad entry! Here's a few things I corrected:

I (我）in English is always capitalized, as is the beginning of each new sentence.

Songs are mentioned in quotes in English, like this: "Tell me why". (We usually capitalize each new word in a song too, but this isn't always true.)  So,  <An angel> = "An angel"  ;-)

In English, the plural of a word ending in f  turns into "ves". Drop the f, and add the ves. (There will be irregular plurals with f, though, so be careful!)

The phrase is, "crazy about". Whether for a singer, sports or a TV show.

Also, "the same as" is a standard phrase, too.  Example: You speak English, the same as me!
Note: The phrase, "just like me" also works well here, but there will be nothing between like and me.

"it initially was" - This is past tense, so I had to change it from initial, and put a "was" to indicate the past.

"concert in China"- Instead of "China-concert" looks better in English. I know that in Chinese, you state the largest place first, then work your way down to the smallest place (ex. China, Zhejiang Province, Hangzou, 335 Beijing Road...). In English, it goes the opposite way- from small to big!

I hope this helped you out!