Not sure this is the right place to ask, but I'm really a newbie about mining and I'm trying to understand. I started mining on CleverMining today and I see that most (90%) of my earned balance is classified as "unexchanged", is this normal and, in case it is, how long does it take to have it as "ready for payout"? Thanks all for answers
It varies, but generally within 24-48 hours you'll have a steady flow of "ready for payout" coins roughly matching pools displayed BTC per MH/s rate. You will always have some immature/unexchanged coins simply because these processes take time. You can also expect to have ~0.2% of "dead" unexchanged balance over time, which is what the poster above calls scam, so you might want read this too:
https://bitcointalk.org/index.php?topic=448649.msg8138087#msg8138087Any questions - feel free to ask.