What sort of rental properties are in demand?
However be careful. Lots of Wanted adverts doesn't necessarily tell the whole picture. Are the adverts for entire properties or just rooms? This could be influential on whether you wish to rent out a house for a family or buy somewhere geared up for bed sits and house shares. There are different legal and safety requirements for shared properties which you will need to be compliant with.

You also need to compare the number of Wanted adverts with the number of To Let adverts. The most promising scenario is an area with many Wanted adverts but not very many To Let adverts. This ratio would suggest an encouraging climate in which to invest in a rental property. Check this sort of information from a number of sources rather than just one, before you make a firm decision.

Which areas have the highest rental yields?
This does not always correspond to the same areas you will find with the healthiest rental market place. But if you can find somewhere that does - you are beginning to get somewhere.

Do you really want the hassle?
It's a bit like the RSPCA adverts about a Puppy being for Life not just for Christmas. Being a DIY Landlord is hard work. It requires skills and research to do the job properly. However if you do find it's too much for you, there are many great letting agents out there who will take the stress off your shoulders. But make sure that you factor in this possible extra expense when you are doing your sums. You don't want to spend all that time and effort and money and then end up spending all your profit on management you hadn't bargained for.