If you find yourself in the position of having to take over the management of your parent's finances, this recent article by Bankrate is a good place to start. It lists the 8 steps you should take:
1. Find All of Your Parent's Financial Accounts and Documents
2. Collect and Start Paying Bills
3. Locate Power of Attorney or Living Trust
4. Open Your Parent's Safe Deposit Box
5. If There is No POA or Living Trust, Become Your Parent's Guardian
6. Document Everything You Do On Your Parent's Behalf
7. Consider Hiring a Financial Planning Team
8. Consider Updating Your Parent's Investments
If your parents are still able to manage their own finances, but may need some help down the road, encourage them to have a Durable Power of Attorney or Living Trust drawn up, so that you will be able to assist them when the time comes.
Without a DPOA or a Trust, it may be necessary to pursue a guardianship or conservatorship if your parents become unable to care for themselves and their financial affairs. This is a costly and often emotional process because it involves having your parent declared unable to care for themselves, and involves the Courts. With a DPOA or Trust, your parent gets to choose who they want to appoint as their agent, and the agent can act at any time with the parent's permission, or when the parent becomes unable to act for themselves.
And while you are at it, don't forget to have your own Durable Power of Attorney or Trust drawn up so that your children can assist you when the time comes...