Which is better for a lap top, keep it charged up all the time, or when I use it? Or after I use it?

Laptops run at higher performance on AC power typically. There are various auto-settings changes.
If referring to the time by which you will want to replace the battery because it does not hold a charge long enough to satisfy you,

A battery wears out mostly by number of charge cycles.
A battery wears out faster in higher temperatures.
A laptop without a battery running AC power cuts out if the AC plug slips and that can cause serious registry issues requiring a complete reset of the laptop as a restore.
Batteries last longest at between 55% and 70% charge levels, but I believe only some Thinkpads have that ability.
Many batteries of laptops today are encased in the laptop and not easily removable.
After full charge, when plugged in, laptop batteries stop charging.

So, the longest life is removing the battery completely, but doing it too much also increases the chance of damaging the connector it plugs into.
The next is if able to run on AC power, it is better for the battery than running it on battery to purposely do charge cycles.
If your laptop had a battery management to hold it at 60%, that is good.

In most laptops, if you usually run by an outlet and battery can be removed and kept out most of the time, that would last longer.

For most people, a battery of a laptop is a maintenance item. People want convenience. When you need a new battery, buy one. Plugging the power cord in and out damages the DC input jack for most of those plugs. Lenovo has a new plug that improves it from the single pin and spring connect outer connection.

If you read through all this, you will either figure out that you can't "win", or will find your own best way of running it.