Need tutorial about mastering.

[picato]

There's a lot of information on the net. Just try an ordinary search engine with phrases like "mastering" + "tutorial", "tips", "eq", "effects" etc. Many online magazines about recording and music have their own tutorial sections that's really good.
Mastering and mixing isn't something you learn by just reading one article though... I've found a lot of articles on the net that has been useful as a start, but you have to practice and experimenting on your own alot as well. I can't recommend one article that's been outstanding. I've read hundreds so far...