[WARNING: THIS TOPIC IS VALID UNTIL MONDAY JULY 31 2017 AT 00:00:00 GMT]
1 - Make sure that you hold the private keys of your Bitcoin addresses .
Q: What if i'm keeping my coins in an Exchange ?
A: In this case, you don't really control your coins, and you might not profit from the new Bitcoin Cash (Free Bitcoins).
Q: What should i do?
A: Send All your Bitcoins to a wallet that you really control [YOU SHOULD HAVE THE PRIVATE KEY], such as Bitcoin Core Wallet, Armory, Electrum, a hardware wallet, a paper wallet (The fast way) ...
Q: How to create a paper wallet ?
A: Here is how : https://steemit.com/cryptocurrency/@bad.r2017/how-to-create-a-paper-wallet-for-any-cryptocurrency-in-7-steps [At your own risk]
2 - DON'T MAKE ANY BITCOIN TRANSACTION VERY SHORTLY BEFORE AND AFTER AUGUST 1st UNTIL THERE ARE REPORTS THAT THE BLOCKCHAIN IS READY TO USE (After August 1st 2017 | 12:20:00 pm).
Q: What if i sent some Bitcoins to someone 10 hours before August 1st?
A: You'll lose your coins, you should wait until August 1st 2017.
Q: What if someone sent me some Bitcoins 5 hours before August 1st?
A: You'll not get those coins, and he/she will lose them. You should stop accepting Bitcoin payments.
For more infos : https://bitcoin.org/en/alert/2017-07-12-potential-split