Here's the scoop on timeshare deductions:
Unless you rent-out your timeshare to others regularly, you may have no deductions related to the timeshare.
If the property taxes applicable to your timeshare unit are billed separately(California), those are deductible. They should also be deductible if your resort shows them as a separate item on your maintenance fee billing statement.
If the timeshare was financed with a home equity loan on your personal residence or by refinancing your mortgage on that residence, the interest is generally deductible.
The annual maintenance fee is not deductible. This is an annual fee for upkeep(utilities, pool care, lawn care, other maintenance, management, etc) and can be compared to similar expenditures that you might incur on your primary residence, which are also not deductible.