If you don't have the time or interest to manage investments, you need a financial advisor.
Generally speaking, you're better served by an advisor who collects an annual fee based on a percentage of your account value. Advisors who are compensated based on transactions have a vested interest to churn your account, which is often not in your best interest.
You also need to be wary of advisors who peddle expensive mutual funds with sales loads (aka kick-backs to the advisor) or annuities. Your advisor's compensation structure should be transparent as well.
A financial planner can help with investments, insurance, estate planning, budgeting, retirement planning, saving for college, tax planning/prep, and other money topics.
One way to get a sense is to look at this Certified Financial Planner topic list.
Another idea is to look at this book (my favorite I've read) which covers roughly a similar topic list in a concise form: Smart and Simple Financial Strategies for Busy People It could not hurt at all to read that before deciding to visit a planner, so you have baseline knowledge.