Staking will become effective exactly from moving from Block 475200 to 475201. By then the Liberio Wallet will have been released and it will offer the option to "cold stake" as broesel mentioned.

As the block time is set to 60s in the network it should happen around end of september start of october this year.

You can check out the whitepaper for more details.

https://alqo.org/whitepaper.pdf