I think it's a great idea to keep a log. Logs are a great way of staying accountable to your study, and if you keep it here (like zaffar does), other users will be able to provide feedback as well as learn from you.

With regard to starting over--it's important that you have a different strategy for studying that you did before. I would really focus on identifying your weaknesses and improving on them with lots of practice questions and discussion with this community.

Do you know where you are weak on the GMAT? What do you think would have helped your score better on your first test?

And don't forget to review every problem you do. Really pick it apart - spend two to three times as long examining the problem as you spent doing it in the first place.

If you didn't do this the first time around, go back and do this for problems you've already done. You're not really finished with a problem until you know that if you put it away and pull it out in a month, you'll know exactly how to tackle it. (Not because you've literally memorized that exact problem, but because you've learned what to do for all of the different problem types, content areas, etc. you might see on the test.)