I'm a big fan of tracking all-diet, exercise, etc. especially when first starting a new program. I'd also recommend a food scale when you get started to help with learning what 4 oz of fish looks like, for example. You will be amazed at how tiny most real "portions" are vs. what you are served in restaurants.
Lots of people I know use
fitday to track nutrition and workouts. You can get your own free online account. I personally created my own system in Excel. Other folks I know like
dietpower.
While I tracked every gram of food, every spare cashew, for 2 years, these days, I only start tracking rigorously when I get off track. It helps me identify where the issues are and helps me clean up my program.
I also like
muscletank for tracking my progress.