There is an upcoming fork of the Ethereum blockchain named Constantinople Hard Fork dated to happen on January 16, 2019. I would discuss a few points regarding this in case you are new to this "forking" events and are confused about what to do to prepare for it.
Hard fork is when there is split of the original blockchain in two separate blockchains, in general like the previous hard fork a few years back which led to the formation of Ethereum and Ethereum Classic. However for this hard fork the miners have not yet shown any deviation from a general consensus of a single blockchain and thus till now there will be only one chain to be followed namely Ethereum even after the upcoming hard fork.
About the advantages that Constantinople hard fork there are some changes that will happen with forking:
Constantinople will delay the difficulty--bomb that is about to happen later this year when POW moves to POS for the network.
Reduction of mining rewards from 3ETH/block to 2ETH/Block
Constantinople also includes 2 further upgrades – EIP 145 and EIP 1052 – which will improve ease-of-use for smart contract development and streamline certain operations within ethereum’s code.
You can read about these here : https://www.coindesk.com/what-to-expect-when-ethereums-constantinople-hard-fork-happens
What you should do before the fork happens :
If you have your ether in a wallet whose private key is under your control like Mist, MEW or a hardware wallet then nothing. Yes you dont need to do anything. Let the fork happen and await further news from the developers if any.
If you have ether in your exchange, then some are going to support he fork and you should look if they are allowing that otherwise withdraw them to a wallet over which you have control. In general its always safer to keep coins in your own wallet than the exchanges.
What you should NOT do:
Do not trust anyone asking you to send their coins to wallet address posted on twitter or any website. Those are scams and will lead you to losing your funds. There are already several of them being made viral to scam innocent people.
There have been some scam "forks" already being promoted on bitcointalk. Never send your private keys to anybody who claims to help you in the fork if you give them the private key.
Under any situation do not panic about the fork or ask strangers on forum or telegram groups for help. You will get scammed by them
Do no fall for any "doubling deals" - remember that Greed will kill << Wise words by wise people.
I will try to update this post will more information as time passes and if any relevant news is posted. In the meantime feel free to ask questions if you have any.