I have only been counting calories a short time, but I am using FitDay, a free online diet & fitness manager. You can also buy a programme to install on your PC, but I am finding the online version just fine. It's a bit of trouble to enter your portions, but it gets easier the longer you use it, as it saves your recent info.
It also calculates the right calorie intake (and recalculates as your weight changes), as well as keeping track of weight changes and activities. I am finding this really helpful to keep a running total of calorie intake every day. You can find it at http://www.fitday.com./WebFit/Index.html