http://stackoverflow.com/faq#reputation lists their points.
You can't make everything exactly the same - for example Q2A has the same points for upvotes and downvotes on answers, whereas SO is +10 for upvote and -2 for downvote on answers.
Here's a possible list of values from Q2A that roughly match Stack Overflow to help you out:
Posting a question: 0 points
Selecting the best answer for your question: 2 points
Per up/down vote on your question: ± 5 points
Limit from up votes on each question: +100 points *
Limit from down votes on each question: –20 points *
Posting an answer: 0 points
Having your answer selected as the best: 15 points
Per up/down vote on your answer: ± 10 points
Limit from up votes on each answer: +200 points *
Limit from down votes on each answer: –40 points *
Voting up a question: 0 points
Voting down a question: -2 points
Voting up an answer: 0 points
Voting down an answer: -2 points
Multiply all points: ×1
Add for all users: 1 *
* = personal preference, you may wish to scale that however you like. Personally I start users with 20 points, and give +/- 10 for every vote, with +200/-40 limits.