Plagiarism
The Steemit community is looking for you to add your own personal touch to your articles.
Plagiarizing, that is posting someone else's work as if it were your own, is very frowned upon by the Steemit community.
If you are using anyone else's material as part of your posts (including images) - please cite your sources.
Also, make sure that you are not violating any copyright laws if you are using someone else's material/images. Limited, sourced material sharing is OK under fair use and fair dealing doctrines.
Password Security
Your Steemit account is worth real money. Treat your Steemit password like you would your bank password, and keep it secure!
Unless your password was recently changed and you possess the old one, there is no password recovery for Steem accounts. You are 100% responsible for having it backed up. This means secure digital backups, as well as secured paper backups, off-site if possible.
Earning on Steemit
The best attitude to have is to expect to make nothing. Have fun. Get engaged. Make friends. If along the way you earn something - bonus!
It is possible to earn thousands of dollars, but most authors who are doing this have put in a lot of time and work to contribute to the community and build followings.