If you're looking for answers to confusing retirement account questions, here's your chance: Over at Wise Bread, David Loeper, author of Stop the 401(k) Rip-Off, is currently answering questions in the forum.
Here's an excerpt of his explanation for how a stay-at-home mom should save for retirement:
Well, the first thing you need to remember is that you effectively own half of your husband's retirement plan benefits and you accrue spousal social security benefits, as well. You cannot make contributions to an IRA without earned income.... You can, however, open a spousal IRA, provided you file a joint tax return.... The other thing you might want to consider is getting a part time job with an employer that allows you to defer most of your income to your 401k plan. This would enable you to accrue your own social security income benefits and to sock away a lot of money in savings, and if you defer your income into your 401k with your new employer, it wouldn't affect your joint tax bracket.