This will be a brief newbie guide based on the many questions I have seen today and an effort to compile some links and resources all in one place :)
If you had a steem account prior to this fork you will have a HIVE account automatically. If you were not on the excluded list you will have received an airdrop that mirrors the state of your account exactly!
This included your liquid steem, steem power, SBD, delegations, witness votes, previous posts etc. EVERYTHING should be mirrored exactly.
Currently there are two options, https://peakd.com/ (recommended) and https://hive.blog/.
On PeakD you can use the integrated peaklock system. This will be shown when you click the login button, or you can use the new hive keychain. The hive keychain has not been officially approved by the chrome/firefox extension stores yet but 
@themarkymark/how-to-install-hive-keychain
Last option is hivesigner (the new steemconnect), here is a post about it: @good-karma/hivesigner-released-and-ready
There is currently some confusion with nodes and people have been accidentally posting where they don't mean to. If you wish to use steem on a steem frontend, set your old keychain node to steemit api, setting it to anyx may result in a post on hive and will show a weird STEEMHIVE hybrid in the wallet section. This section may be updated as things progress.
Using hive keychain on PeakD should work without issue
Q: Why doesn't X work?
A: Please be patient as various pieces of infrastructure are ported over to the new chain. Many dapps have stated that they are moving over but some may not, here is an incomplete list:
(Please contact the individual projects for more details)
Q: Where can I trade HIVE?
A: Be patient. Exchanges are being brought online. It's standard procedure for them to prevent deposits and withdrawals during a chain hard fork, especially with an airdrop involved.
Currently Trading:
https://global.bittrex.com/
https://ionomy.com/en/markets/btc-hive
Remember: not your keys, not your coins. Use centralized exchanges with caution. Do your own research.
Also we are now on coingeko!: https://www.coingecko.com/en/coins/hive
Witness voting
I highly recommend that on HIVE you go back to your normal witness voting, many of us adjusted votes to the current top 30 strategically but on HIVE we no longer need to do so, rearrange your votes as you please!
Please note that the influx of question is very heavy though that seems to be cooling a bit! Have some patience with your helpers as they are doing their best and always check pinned messages and info rooms if you can because your question may have already been answered 100 times ;)
Not everything is working as intended and that is normal right now. Don't panic!
HIVE discord server: https://discord.gg/EMgXs5N
Palnet server: http://minnowpond.org/
If you tweet about HIVE on social media use the tags #hive, #hiveisalive and/or #hivehasarrived, have fun!
