In the first few weeks to a month after your baby arrives, you will be learning baby's hunger cues. The feeding schedule may vary from 8-12 times a day. As a helpful reminder, knowing the last time you fed will give you a general sense of whether the fussiness, rooting, etc. are hunger cues.
To help, a friend made me a breastfeeding bracelet and imparted on me her wisdom as a new mom: your sleep-deprived mind will lose track of time and this bracelet will help you remember when your baby last fed and which boob was used for the last feeding.. Being six weeks into mommy-hood, I agree with her and thank her for making me this beautiful bracelet.
This breastfeeding bracelet has numbers 1-12 to represent the hours and 4 beads in between the hours representing 15 minute blocks of time. To use the bracelet, place the clasp (this one happens to have a charm that says "made w love") to the time your baby last fed and place the bracelet on the wrist that corresponds with the boob that was used for the last feeding. The bracelet is beautiful and to the passing eye it is just that - a bracelet. Little do others know it serves a purpose, too.
I prefer this low-tech way over using a smartphone application because it keeps things simple. The first week I used WebMD Baby (free app you can download at http://tinyurl.com/7qstdpy) to track the exact minute I started and stopped breastfeeding, which provided a log of how long and how frequent feedings were. It was interesting to know how many hours a day were spent breastfeeding, but I found switching away from the mechanics of it all allowed me to focus on learning my baby's cues instead.