First, it is advisable that after the divorce is final you update your will by revoking it and creating a new one. If you do not wish to wait for the divorce to be final, you may do this prior to it being final. By doing this you are able to start over fresh with a new will with new assets and beneficiaries. It is advisable to wait until an equitable distribution is final, however, as this will allow all parties to know exactly what assets (liquid and physical) should be included in the will.
It is next important to revoke your Power of Attorney. A Power of Attorney allows your spouse or ex-spouse to make many important decisions for you if you should become incapacitated as well as allows them access to your finances and personal, private information.
Finally, as general advice regarding the important first steps in estate planning after divorce, you should reassign and update your beneficiary designations. Things such as life insurance, your 401(k), and any trusts you may have will need to be immediately redirected to new beneficiaries. These are a few estate planning considerations when going through a divorce, however, for more information, you should contact a family lawyer as well as an estate lawyer.