Katymac I used to own a house which I bought and rented out.
While you are renting it, teh rental income is taxed at the rate at which any income you have would be taxed. So if you do not have any other income, you will get your normal yearly allowance, then 10%, etc etc, just as if it were income from work.
There are lots of things that are tax deductible - agents fees for letting it, any maintenance costs, etc. These can add up to quite a lot, keeping your actual income low.
The crunch is when you actually want to dispose of the property. The longer you have it, the less capital gains you pay. If you keep it for at least 10 years, you will be paying the minimum amount possible.
Capital gains tax is not taxed at 40%. Again, it is taxed as income, so if you don;t work, or have any otehr income, you will be taxed accordingly.
You can get books out of the library about all this, I never had any "professional" advice, just read up on it and worked it out!
I would say it is a good idea as property values rarely fall over the long term and in some areas are still forecast to make big increases.
HTH!