One of the most important things you can do is to make copies of all financial records. This includes the mortgage, pension statements, income tax returns, investment account records, insurance policies and similar paperwork. The more documentation you have for these types of assets and liabilities, the better you might fare in your divorce. They can also help you determine whether your ex is trying to hide assets.
Another important step is for you to check your credit report. Make sure that things are being reported accurately. If you see any suspicious entries, investigate to find out what is going on. This might also help you to find joint lines of credit that you forgot about.
You should cancel all joint credit accounts. This might not be as easy as it sounds. You may have to pay it off in full, but it might be possible for one person to transfer the balance into an account with only that person as the account holder. At a minimum, put a freeze on these accounts so that no more charges can be made on them.
As you work to rebuild your life after the divorce, make sure you are following a budget. This can help you from making financially devastating mistakes.