I tried out Logbook Pro and found it 'over the top' for the average
private pilot.
I'm now using ForPilots Logbook (look on Google). You can choose which
fields that you want to activate and forget about the rest. Also allows
you to display some really cool graphs once you have all your stuff entered.
Best of all, it's shareware - you can use it for free for ever if the
nag screen does not irritate the hell out of you. I think its about
$US26 if you do choose to pay the fee.
Peter