The simplest thing for you to do is walk into the lender that gave you the home loan to buy your house and ask for a buy to let mortgage. You may even get the loan that you want. However, as an investor, it is important that you take the time to compare buy to let mortgages before you settle on the right one.
You can find a great deal on your mortgage with a mortgage broker. The mortgage broker will compare buy to let mortgages and find you the right one for your needs. However, you should be aware of the fees that are involved when you use a mortgage broker. This may be a fair price to pay to find the best interest rates for your mortgage, but calculate the costs in advance and determine if you could do as well on your own without the fees.
Ask for quotes from the various lenders to compare buy to let mortgages. Make sure that you take a look at some of the alternative lenders that are available that may be a good resource for your mortgage. Once you have a good listing of the various lenders that are available, you will be able to make the best possible decision on your buy to let mortgage.