@boxmining does a great work and explain some of the currencies and ICO's

But yeah the more you will read the more you will understand what are blockchain technologies and you'll be able to make your own opinion about them.
I don't recommend to read first the dedicated reddit thread of a blockchain, because people are so overhyped and there are no debates.
Check out https://www.reddit.com/r/CryptoCurrency/ the global thread.

Also for tokens and cryptos I found a website which explain what tokens are used for.
https://tokenmarket.net/blockchain/all-assets

Hope you'll find what you need :)

Feel free to follow I try to explain some of them :)