how secure the paper wallet if i create and print it from the websites like bitaddress or etc, do the owner of that website known about the private key 
When you use my own generator (bitcoinpaperwallet.com) there's a helpful "security checklist" that tells you how secure you're being.
https://bitcoinpaperwallet.com/bitcoinpaperwallet/generate-wallet.html
The trickiest part is creating an Ubuntu Live CD with the wallet generator pre-installed (so that you never have to go online). I actually sell a product to make this easy:
https://bitcoinpaperwallet.com/ubuntu-linux-live-bootable-cd/
