Most houses are sold through Estate Agents. They will be much more interested in you as a serious buyer if you're clear on what you want ie have a specific location in mind, an idea of the house's size and the price you can afford. A mortgage in principle will reassure them, and their clients, the sellers, that you're a serious buyer worth spending time on.

Contact the Estate Agents local to your desired area and ask for their list of houses for sale. Look through this and then ask for further details or particulars of the ones you're interested in.

Make a note of what you've asked for because often they don't get sent and you'll have to chase them up.