I have to say keeping a garden journal is an essential tool to successful gardening. This is the third year I've kept track of what I've planted. 

Some ideas of what to write in your journal: When you start seeds, how much soil you ordered and where you got it i.e.: 4 yards of compost from Grimm Fuel. I also keep track of the when my hops starts to show, what birds I see at the feeder and any construction projects I do that are garden related. Once you get started it really helps plan year round gardening.

Also record what varieties produced well to help your seed ordering and troubleshooting for the following year. i.e.: Planted Black Prince, yield was poor, must move to sunnier place.