If you own your house release as much equity from it ie bank loan and buy another house or if you have to get 50% mortgage, whichever will yield most annual income that's the one you rent out, eventually you will own 2 properties
Am sure you have watched "Homes Under The Hammer" there are 10's of thousands doing this already and it all boils down to buying the right house at the right price, helps if you can do most/all the renovating yourself as the most gain seems to come from the most run down properties