Vat Claimable and non claimable

Dear All,

Can you clarify

1. when is VAT claimable and when it is not claimable

2.If i am adding Packing and forwarding charges on vat and frieght +vat  will these come under claimable portion or non claimable portion.

3.What are the different heads which can be added on VAT. I mean frieght,Packing and forwarding charges etc.

Thanks in ADVANCE

Bhushan