Yes, there are a few important reasons why you should talk with your Mortgage Broker or Bank before you start looking at homes.
Firstly, depending on your comfort level and needs there are benefits to using a Mortgage Broker over a Bank and vice versa. The most important part regardless of Bank or Mortgage Broker will be establishing how much you can borrow for your home purchase. It is crucial for you to know your budget in order to effectively find potential properties whilst house hunting.  
Secondly, by communicating with Brokers or Banks you can learn the options available to you depending on your financial situation and on the property type you are interested in. There will more than likely be different strategies you can apply to get the best possible deal on your mortgage with regard to rate and terms.
Finally, when submitting an offer on properties it goes a long way to be able to provide the assurance to the Sellers that you are pre-approved, it shows the Seller that you are serious about your home purchase. Depending on the type of real estate market you are in this can help tremendously.
If you have any questions or need advice on anything real estate-related don’t hesitate to reach out!