1-Where should I look to find future ICOs? Is there a forum, a blog or a trading platform for this?
https://santiment-slack.herokuapp.com/I'm following the slack group, and the group is coming up with good conversation about the upcoming ICOs.
It provides a lot of knowledge for you. I believe it.
2-What are the characteristics I should looked to maximize my chance of picking some profitable ones?
The profitable ones for you will never give a non-sense innovation for the project.
3-Are there any popular and successful traders in this field that I should follow to get useful insights?
No, The promising project will always be having mass supporters.
Like what was happened with Gnosis and Aragon.
Status will be the next one.
4-What is the best way to buy early when I find some that I like?
Buy on their crowdsale and get your bonus.
5-Is there any stats somewhere about past ICOs?
Here
https://icostats.com/