https://bitcointalk.org   Here is the benchmarking community for cryptocurrency, and there are many experienced users are happy to share their insights, so most of the time I am here to learn the knowledge of cryptocurrency.

https://coinmarketcap.com/   I can check the average current price of cryptocurrency and make a reference for the transaction.

https://twitter.com/   Occasionally I will come here, mainly to know about some news about cryptocurrency, as a supplement to bitcointalk.