Try these websites for online listings of rental properties. You can even set up an account that will automatically email you houses for rent in the areas you want, in the price range that you can afford.
Community and university notice boards are good places to look – especially if you are looking for share accommodation.
Real estate agents
If you know the area you would like to live in, check Google or the Yellow Pages for real estate agents in that area. Contact the agents by phone and introduce yourself. If you represent yourself well (be polite and be clear about what you want) a real estate agent may choose to help you out and let you know if something suitable comes up.
Every week newspapers publish a “To Let” and “Share Accommodation” section. You will find that Wednesday and Saturday papers have the largest listings. Your free local newspaper is also a great way of looking for rentals in the local area.