I commend you for your honesty and think your wife is lucky to have a husband that wants to work on saving the marriage. The best way to begin the healing process is to talk with each other. Allow your wife to share all her feelings with you, positive and negative. Listen and reflect back what you have heard, to show that you have understood. Never, under any circumstances, fall prey to the temptation to justify or defend yourself, just listen and understand.
After the venom has been drained-off, then both of you need to begin honest discussions about what went wrong in the marriage. These discussions shouldn't be a blame game (you did this to me, well you did that to me). In order for these talks to be productive, you both need to engage in honest self-examination and figure out how each of you contributed to the erosion of the marriage.
For example, you spent too much time on the computer, became disconnected from her and had an affair. But, what wasn't working for you in the relationship? What caused you to bury yourself in the computer in the first place? The key here is not to sound like you are pointing fingers at the other. (Well, I wouldn't have buried my face in the computer if you hadn't done x, y, or z. )
I hope you get my point. After you both have come up with honest answers about what was missing in the relationship, then work on correcting these issues and problems. My best wishes to you. If you need further help in healing the relationship, please let me know. You are a wonderful man and an inspiration for all the men out there who have slipped and want to come back.