List of cryptocurrencies marketing stuff. Everything in one place discards the need to open plenty of charts.
https://www.worldcoinindex.com/
Choose your GPU rig or ASIC units and get estimated rewards per day. Also you can find here exchanger with the currently highest price. Remember, it's not good time to use Poloniex now. A lot of users tell, they cannot withdraw their coins to really long (going to infinity) time of approval. Read some news first, and if everything is fine, play there.
https://whattomine.com/
List of GPUs with their hashrates. Useful if you need to understand what the ROI will be before buying hardware.
http://62.212.74.86/~mining/list/index.php?brand=both
Down here there are some pools and services where you can start digging into mining world.
https://www.nicehash.com/index.jsp?p=gstarted
https://slushpool.com/home/
https://en.minergate.com/
https://www.epool.io/#/
https://zclmine.pro/#/
Just remember, before doing anything in CC world, find corresponding threads at bitcointalk.org and make sure service is not listed at badbitcoin.org.