i would like to know more about analytical method validation in detail. (not theory - the practical part of it ie. actual validation work and calculations?
There are many textbooks available on validation, and many resources on-line. The "free" resources will not give much information. If you want to learn about validation you must buy the books, or attend a training class.
The topic is too complex to be discussed in a forum like this. If you have specific questions we may answer them here.