You can check
https://coinmarketcap.com/new/ and see which are the new coins that has just been listed.
Important to also make sure that the coins are listed on an exchange.. else you wont be able to sell your coins anyway.
New coins are never on a exchange at the beginning of mining. It's a risk mining shitcoins but the return can be very nice as well.
Best place to find new coins to mine is in the announcement section right here at bitcointalk.