Whether you are a resident or not, you don’t (at the moment) charge IVA on your rental income. Unless you are renting the property to a registered business, in which case you must charge IVA, at 10%.
You must charge IVA on any services you provide i.e. cleaning, transport, catering. The invoices you receive pertaining to the property (with IVA) are costs deductible and can be offset from the rental tax declaration. Also home insurance, mortgage, rates and community fees are deductible and offset from the rental income.
If you are a non-resident using a management or property agency to manage your holiday rental (whose company is registered with the social activity of ‘explotación de bienes inmuebles’), then you must be registered for IVA (VAT) in Spain to receive your rental payments from them.
If you using the services of a management company, they should retain the 24.75% from your rental income to pay to Hacienda (tax office) in your yearly accounts. If you choose to manage your property independently, you will need to register yourself with the tax office as charging IVA and make sure you retain 24.75% of your earnings for end of year tax purposes.