The first tip I can give is to collect a file of documents reflecting your economic life during the marriage.
Most economic issues will be determined based on the income of the marriage, the spending during the marriage, and the holdings of the marriage. Collect the documents that reflect those aspects of the marriage. For income, gather tax returns and pay stubs; for spending, collect credit card statements, canceled checks, and household bills; for the holdings of the marriage, collect bank and investment account statements to show assets, and credit card and loan statements to reflect debt. Do not worry if you do not have access to some or even all of these records, as your attorney will be able to obtain them by way of discovery and subpoenas.
My second tip is to consult with an attorney.
A good consultation should provide you with a general understanding of the legal issues that will impact your divorce. While no lawyer can tell you how your case will end, a good consultation will give you the range of reasonable expectations that you should have going into a divorce process. Being educated as to your case is key, and consulting with counsel is the first step towards educating yourself.