Keep Money in Your Name
You and your husband should have joint savings for things your family may want in the future: a bigger house, for example, or a college education for your kids. But it's also important for SAHMs to have some savings in their own name. If you don't already have one, open an individual retirement account (IRA). You don't need to be working to contribute up to $4,000 ($5,000 if you're over 50) to a spousal IRA or to a Roth IRA. (Talk to a tax planner to determine which option is best for your family; it all depends on your age and your income.)
You should also have at least one major credit card (not a store card) in your name alone. Be sure to use it -- and to pay your balance on time every month. This will establish your credit history, which is essential for taking out a mortgage or a car loan. If you only have a card on your husband's account, he could easily cancel it if you ever get separated or divorced.
Finally, make sure that your house -- typically a family's biggest asset -- is in both your names (unless there are unusual circumstances, such as special tax considerations or a prenuptial agreement).