Thats an intelligent idea , we had blogs about everything but not about our dear plants , really you should try this out faisal's Diary of an Avocado tree.
Given the speed at which an avocado tree grows i bet you will get some really nice entries until we get to reap the fruits. Some nice photos are available at this time its only about 2 months old. We learn that our avocado friend migrated from Mauritius as a seed and now lives and grows in England.
It also likes eating a blue thing but that's up to your to find out what it is hehehhe.