That's OLD info and only relevant to old Nickel chemistry. Modern NiMh batteries "may" benefit from a cycle once in awhile but generally not. Just charge them when they get low. Don't leave modern LSD-NiMh in a trickle charger.
A lot of the info you get off the web about batteries is poor, especially from self-proclaimed experts.
Lead acid batteries prefer to be fully charged, all the time. Full discharge is very bad for them.
Lithium ion is a whole different chemistry. +1 on what WetEV said.
Try to keep it between 20-80%. Fully charge if you need it, but try to not have it sit fully charged for long....especially if it's hot. Full charge + heat = battery degradation. Very low is also not good, along with anxiety producing. When my wife got her first low battery warning she kind of freaked, even though she was only a few miles from home and had plenty of reserve left.
How you do that is up to you and your use pattern. If your use is predictable (regular commute) and your Leaf has charge-timer option you can likely set that. If not you'll need some other mechanism.
I've had mine about 6 weeks now and am getting more used to what I do with it, how long the battery will last, and how much charge I put back in a given time frame. (big improvement when I got 220v). My schedule is completely random (retired) so I haven't found the integrated timer of much use. I just try to keep 'enough charge' but not 'too much' and err on the positive side.
This is a good source for decent battery info. http://batteryuniversity.com/