You must use a fully charged battery within 3 days. Leaving it sit either fully charged, or discharged can damage the battery. So below is advice on good habits you can develop depending on your usage:
ALWAYS charge to full before EACH USE - including the first time out of the box!
Always charge to full even if you only used it a little bit the time before, the final stage of the charging balances the voltage in the internal cells; using it without fully charging/balancing the battery may permanently damage it.
If you will be using the battery every day (or even every two or three days) - a good habit will be to charge the battery after each use.
If you will be using the battery less than twice a week - it's best to charge the battery ONLY to the storage voltage until you're ready to use it again & then charge it to full just before you're going to use it (the day before is fine).
For voltages specific to your battery - click on the appropriate category in this help center and find the article referencing the minimum and maximum voltages.