This link has been posted before about going from cheating to polyamory and I think it's fitting. Keep in mind the author is very anti-cheating. I'm of the opinion that it's VERY hard (impossible) to go straight from cheating to polyamory. The dishonesty inherent in cheating badly damages the trust and intimacy needed for ANY relationship to thrive. Trying to go from an affair directly into polyamory is akin to breaking your leg and then hopping up and trying to train for a marathon. Better to put the marathon off until your leg heals, IOW, work on recovering from the affair BEFORE jumping into ethical non-monogamy.
Since this transition period seems unlikely, Wife and I found the book After the Affair by Janis Spring helpful after she started "poly" with an online affair.