Will be file lost because of upgrading (from 10.4 to 10.6) ?

Good evening!

I write one month ago post about upgrading my iMac with operation system 10.4 so today arrived finally instal DVD.

I think I should read at first how to instal Snow Leopard

If I install it,will I lose all my files like music,videos,pictures in all folders I have?

I hope I will get answer soon.

Every help is thankful!