The best tax tip I can give you is to get started early, file on time, and consider using the services of a professional accountant so you can concentrate on the things that you do best.

That's not me above. 
Did you know that your principal residence is deemed sold everytime there is a change of use from personal use to rental and vice versa.  You should determine the fair market value at that time, for once you actually do sell the property, you may need to report a taxable capital gain for the years determined to be a rental.   However you may be able to claim your house as a principal residence for an additional 4 years by filing an election with CRA in the year of change under 45(2) of the ITA.  It is important to file the election even though you may not anticipate selling the house.
Window box flowers leads to:
Deductible Business Expense?
The first thing to ask yourself is did you incur this expense for the purpose of helping you to earn business income?  Secondly, for expenses over $500, does it continue to help you earn income beyond the current year (deduct CCA over several years)?  Thirdly, are some personal expenses also legitimately used for business purposes (prorate)?
"Bella" discusses Automobile Log:
You may use your auto or other vehicle for business as well as personal use.  CRA may ask to see your auto log and could disallow your related expenses if you cannot produce one.  However, you are allowed to reconstruct a missing or incomplete log from other information you may have about your daily business driving throughout the year.