Use a mixture of everything.

From ICO sites to news sites (announcing icos)

Reddit its a good place to at least get some coin news and find discords channels telegrams ect.

Otherwise google is your best friend really.

One ICO site is use is https://livecryptochart.com/en/crypto-ico/upcoming I think they pull from a bunch of different places. I also check https://news.livecoinwatch.com/ico/ But don't just use one source, use many and as many as possible.

Anyways hope this helps.

I use https://livecryptochart.com/en/crypto-coins-news-headlines In my personal opinion it is one of the best. Not only can you get news on the site but real time pricing as well. Hope this helps.