Your iPad will suffer no ill effects through being connected to its Power Adapter for extended periods. Your iPad will automatically regulate and optimise charging - and will not overcharge the battery. Other than you ensuring that the iPad is regularly charged - and that you do not allow the battery to be allowed to remain in a fully discharged state - there are no manual interventions necessary.
When used in kiosk applications - where external power is connected for extended periods of time - the iPad may modify its charging strategy and limit battery charge to ~80% of maximum. This modified charging strategy is designed to reduce chemical ageing that might otherwise occur if 100% charge is maintained at all times. Nominal 100% charging will be restored when a normal charge/discharge routine is restored.
More information about iPad’s battery management can be found here:
About iPad and iPhone Charge Management Feature – Apple Support
Batteries - Maximizing Performance - Apple
The iPad User Guide provides guidance for charging your iPad’s battery:
Charge and monitor the iPad battery - Apple Support
If you are being hyper paranoid, keeping your iPad’s battery above 20% may help to prolong the iPad’s ultimate battery lifespan. Similarly, an iPad should not be stored for extended periods with its battery at 100% - approximately 50% charge being recommended for extended storage.
In summary, allowing the iPad to automatically regulate its charge is the most effective way to charge your iPad. Allowing the iPad to fully recharge to 100% will do not harm whatsoever for a device that is being regularly used. Keeping the iPad connected to power for ling periods is not an issue.